I did that once, I was staying at a family as an exchange student and immediately forced to help with chores. Now, they ran a large creche from that house so there were a lot of different chores and being on dishes could mean slaving away in the kitchen for well over an hour.

Anyway, I didn't know shit about how to properly dispose of oil and in the first or second week poured a large pan of oil down the drain. It ended up ruining some stuff and they had a hefty repair bill. I may be cynical, but I never gave a damn about it as they were basically using me as free labor anyway. Helping with household chores = ok. Helping clean up the gigantic daily mess of those shitty kids in your shitty creche = not ok