I guess you would recommend it, then.

My best guess is it's a reference to the film Magnolia, in which it rains frogs. It's not a film I would recommend.

Every time you look at a visible tile, there is a 1 in 10,000 chance of seeing a frog eating a magnolia.

After a couple of days I became impatient enough to cut all the other gods out of my prayer routine; that sped the process up a lot. Locking the kamikaze dwarf's target in place made the final step much less frustrating, too.
The fire system makes me a lot more careful with scrolls and doors. If I let equipment get burned, Loricatus is liable to repair it instead of rolling the dice for adamant equipment. Mellis's free fluids become even more important for dousing things quickly. Sometimes I have a burning item with a tiny bit of liquid on it, and I have to wait for that to evaporate before I can soak it properly. Dwarves' books are especially prone to this. Silva's rain is very unreliable for putting out fires, especially of inventory items. If I'm forced to use it, I seem to have more success dropping items on the floor than wearing them. More than once I've openly carried scrolls of detect/teleport on GC5, and the enner beast has set off an explosion that instantly destroys it. Very annoying
The new ghost visuals are good; it's nice to know what they are without having to examine them. Undead versions of veteran dwarves and high-level mistresses are brutal, and can appear to a character without equipment in UT1. :S
Most of the crashes I've experienced are reported on github and avoidable by the user. Activating fullscreen mode, talking to Ivan, and digging while hungry are all avoidable.
One exception is a crash that I get when a Windows 7 UAC dialogue opens. I probably ought to just uninstall Java.

... Why doesn't Petrus wear a helmet?

Attnam won't be hostile to a mere betrayed pet - the wand of resurrection would have to be triggered (broken) by something other than the player, such as a mine or betrayed dwarf.

Because... I... forgot. :3
Also, experience with player clones has showed me that they always have leprosy and it's difficult to make them drink antidote liquid (I guess that's because I was satiated when those clones were made), so I have a slight aversion to making them.
Heh, yeah, probably. Earlier on in the game I was dual-wielding flaming swords, and focussing enchantments on one of them with the intention of cloning it for the endgame. Then a +5 chameleon whip showed up in the dungeon and turned out to be better than the unenchanted sword. They made a good combo and I wasn't in a hurry to switch to dual whips.
I think the scroll I used to change it to GEF came from the last cloning charge, which meant that the only way to clone the whip was by breaking a wand, which I had forgotten to do.
Yeah, I've done it that way once, but there's a lot that can go wrong in the time it takes Petrus to leave the cathedral. And if you don't have enough explosives to kill him twice, you're back to fighting him (and an archangel) fairly. I've seen that archangel kill Sherarax.
It is possible to make Petrus leave the cathedral if a hostile genie survives the guards and shopkeepers long enough, but that seems an even more unreliable way of getting him into traps. Another option would be to spawn a dangerous enemy in the catacombs and lead it into town. Perhaps with a unique corpse, two wands of resurrection, a wand of teleport, and a mine.

That's why I would have preferred a balsa golem for the job. Unfortunately golem scrolls are scarce, and if I accidentally killed it I wouldn't be able to resurrect it without arms.
When I tried it for real I only dropped two bottles at a time, so that the waste would be minimised if Terry's leg strength did increase during the process.

It doesn't. I just like to have my tools in order so that I don't have to look at the list when applying one.
Also, I use the nethack keys on this computer, and H is under the right hand. Checking the inventory screen, it seems I actually moved it to D. AD is a much more fluent sequence of keypresses than AH, which suits a tool that sees a lot of use.

Massacre details:
A lot of things died while polymorphed by my GEF chameleon whip.
The enner beast died from about 2 direct hits by a wand of fireballs.
Genetrix Vesana was killed by a holy handgrenade, because I was a total wimp when I reached UT3.
Golgor Dhan was killed by repeated zaps from a wand of striking, mostly while distracted attacking a couple of pets.
Guugzamesh showed up far too late to present a threat.
Oree died about as easily as you'd expect.
Richel Decos took more than one hit to kill! Well done to him.
Rondol spawned in GC6 and I forgot him, which had me angsting about the lack of wands of polymorph for quite a while.
Found two valpurium golems! They both got polymorphed before running out of health.
Xinroch showed up in GC10, way too late to be a concern.
Zolku and the banana grower encourager were killed by wolves.
Elpuri was fought by Vladimir and Alvin the angel of Silva, who got the killing blow.
Alvin went on to kill ZQ-29, and I didn't realise until I checked Alvin's equipment and found a spider silk armour. Even then it took a thorough search to find the loot.
Alvin was killed by Ur-Khan, whom I kited to death in 5-10 hits.
No Ischaldirh or Sherarax.
Ivan was killed by a bronze golem while polymorphed into a werewolf in GC8. Silly Ivan.
The sumo wrestler... guess.
Excel's puppy Menchi was killed on the very first level by a zombie of a kamikaze dwarf of Valpurus.

Inventory follows, minus the strongbox full of nonexciting wands:
I never had enough spare cloning charges to get permanent haste and invisibility, and after having to buy books of Valpurus back from the library that was probably for the best.
The stack of whips was for disposing of non-acid liquids given by Mellis.
There's also a large chest at the entrance to Attnam, full of... just about everything that I hoovered up from the dungeon.

Mellis gave me a lot of ommel fluids in addition to the 37 bottles of acid, and the process took about 10 days, during which I liberated Tweraif.
I filled a chest with gold helmets and metal armour, and used it to overload the tamed guard, fixing him in place next to Petrus. I gave only one backpack to the dwarf, in case I needed to try again.
My wand of slow was probably depleted, so I angered him by throwing a ring of teleportation. Took a lot of effort to get him in a good spot.
After the explosion (at 11:37), only 23 bottles were broken (14 remained intact). It wasn't the dwarf's fault! I gave him too few explosives!
Nevertheless, Petrus's head was destroyed on schedule (he died at 11:40).
I had sold 14 books of Valpurus to the library during the game, and it took about 5 of them to become champion and win.

Final score: 1161540

Disadvantages:
* Requires a lot of bottles.
* Requires Mellis, who sometimes isn't available until well into GC.
* Requires a lot of time to fill the bottles with acid.
* Requires a weak humanoid pet to be disarmed without dying.
* Requires a means of taming dwarves.
* Requires pets to be cleared out of Attnam during setup.
* You don't get the Justifer without angering Attnam.
Advantages:
* Doesn't require gas grenades or mines to be saved.
* Doesn't require good equipment, stats, or even fire resistance (as the explosion can be small).
* Doesn't anger Attnam.
* 23 is an upper bound on the bottles required - the real number is probably much less.
* Time can be saved if you start collecting or cloning acid bottles early.
* Cruentus provides infinite bottles, if you can pray to both him and Mellis safely.
* Dulcis provides free taming items, if you can pray to both her and Mellis (and Cruentus?) safely.