Originally Posted by southpawboston

True, oven cleaner gets dumped down the drain, but it's a matter of dilution. Oven cleaner is probably (I'm surmising) a combination of a small amount of concentrated NaOH with foaming agents to allow it to foam up and adhere to surfaces. Per final volume, it's probably not much NaOH. You put it down the drain and run water on top, which dilutes it further.

FWIW, NaOH is a strong "base" and has a pH at the highest end of the scale, at 14. The opposite is acid, which has low pH. If you mix an acid and a base, you effectively neutralize them both and produce salt as a byproduct. That's how we dispose of acids and bases in the lab, by neutralizing them with each other.

Urine is acidic, and we dump it down the sewer all the time. So, if you're really concerned about dumping lye down the drain, dump it in the toilet instead, and urinate. Bam, neutralized.