Two things.
First, I've found what seems to be a reliable way to get rid of Timer0 fluctuation. If your timer0 isn't being consistent but rather fluctuating between two values, warming up your DS (put it in a warm room, under the covers of a bed, next to a computer exhaust fan, or something like that) seems to make it stabilise on the lower value. (You don't need a huge temperature change, or you'll drive it to another value entirely; don't go setting it on fire or putting it in a fridge or anything like that. Also note that it's the temperature of the DS internals that matter, and that'll lag some way behind the temperature of its environment; you should be able to feel whether the DS itself is hotter or colder than the room you're in.)
Also, I've been having success breeding pentaflawless nonshinies, but I've been using a different method, which requires less search time, but more of your own time, and requires power items but doesn't require you to control the PIDRNG. It works like this:
- First, find a male Pokémon with the egg moves you need and of the right nature, and a flawless Ditto. (This can typically be done quite easily, as the non-Ditto doesn't need any good IVs, although it will go faster if it has some; just do non-RNG breeding to breed the egg moves and nature you want onto the Pokémon in question.)
- Search the Time Finder for times which give four flawless IVs (four of the five you want) for Gift Pokémon on frame 8. (There should be around two to three results every month even without keypresses, so this will go quickly.) For the two non-flawless IVs, one should be the attack stat you don't want, the other should be a stat that isn't flawless on the Pokémon you're breeding (there must be such a stat, or it's pentaflawless already and you can just stop now).
- Give the father an Everstone, and the Ditto a Power Item corresponding to the stat that you want flawless, but isn't flawless in the Time Finder results.
- Lay an egg, and RNG it at that frame (at frame 8 no advancement's required, just talk to the Daycare Man immediately after loading the game). You might want to wait a bit first so that the PIDRNG has a chance to become actually random, rather than controlling it to the wrong value by mistake. Only 1 in 4 eggs will work for this method, so you may have to do this several times; it's fastest to control a batch of eggs first, then hatch them all at once. Remember to periodically take the father out of the Day Care to move the egg moves you're trying to breed to the bottom of the list, so that they don't get overwritten!
- Hatch the eggs, with the father out of the Day Care (to avoid his moveset changing), and take them to Gear Station to check for flawless IVs. All of them should have at least one more IV flawless than the father (because all the IVs that were flawless in the father are also flawless in the Ditto, and flawless in the random IVs, so they'll end up flawless, and using the Power Item on a flawless Pokémon forces one more IV to end up flawless). You're looking for an egg that is either pentaflawless with the right nature and ability (1 in 4 chance if the father was tetraflawless), in which case you're done, or that's more flawless than the father, with the right ability, and male (1 in 4 chance if the father was triflawless or less).
- If you aren't done yet, you now have a father with more flawless stats than you did before, so just repeat from the start using the new father.
This should be pretty reliable and mindless, although it depends a bit on luck; and the seeds are easy to hit and easy to find, and you don't need PIDRNG manipulation (it would help in theory, but you're better off using one of the other methods if you can do that). Note that although the chance is lower than 1 in 4, this method can also produce eggs that have more than one stat flawless that weren't in the father (if they randomly inherit from the Ditto instead, a chance that I think is about 1 in 5), so it can even produce hexaflawless eggs if you're lucky. Likewise, if you're willing to put in extra searching time in RNG Reporter to find pentaflawless seeds on frame 8 (this will probably need keypress seeds, as it's rather unlikely with keyless seeds), you can push the number of flawless IVs up to 6 using this method instead.
I'm not suggesting that this method is superior to the ones in the OP (it's rather slower than them); but it's easy to learn and works for me, so I'm letting people know about it in case they have plenty of time but don't have a Chatot (or are missing some of the other things needed for PID abuse). It's also not going to get you a shiny (or rather, will with the same 1 in 8192 chance that shinies always have), so look elsewhere for that.