| | Re: Bleeching the driftwood
Actually, household bleach (NaOCl) is a rather unstable molecule. Given exposure to air, light, etc, it breaks down very quickly into O2 (oxygen) and NaCl (table salt). That's why people who don't use dechlorinator in their water changes often leave the bucket of water out overnight - the tiny concentration of chlorine in municipal water is gone by morning. Or, for another comparison, think of pool water, which is chlorinated. You don't just put a gallon of bleach in a pool and leave it at that for the season, you have to constantly put more in because it breaks down quickly.
The issue with using bleach on driftwood isn't the possibility of bleach itself staying on/in the wood but rather that a) the leftover NaCl can raise the TDS of your water, which may be undesirable for a planted tank, and b) your wood will end up, well, bleached white(ish). White wood isn't attractive to most people... especially if it's done unevenly and you end up with blotchy wood.
If your plan is to use the wood in a high-pH or brackish tank, and you don't mind the look of it being whitened, then you could hypothetically bleach the wood. Just air it out in a well-ventilated place and let it dry completely before putting it in a tank. I wouldn't try it in a low-TDS, plant-oriented tank for the aforementioned reasons, but it wouldn't be inherently toxic or anything once it was cured.
I use bleach to get algae off of really stubborn equipment/rocks/tanks sometimes. Similarly, I use CLR to get calcium and iron scale off of old tanks and whatnot (in that case, it's a strong acid blend that breaks down quickly with exposure). The trick is to rinse well, then leave it outside to air out for a couple days, after which point it's safe to use again.