Is punishment or reward best for teaching kids?

Say you got a bunch of chores for them to do but they're being disobedient, is it better to threaten to take away a luxury for them or incentivise them with a reward when they complete a chore. The kids leave shit fucking everywhere and I'm always picking up after them, I've tried teaching them to look after them selves which work for like 3 weeks then they start doing it again. They're 8 & 9 btw