How long do you leave a joke alone after it dies twice?

I’m trying not to turn two bad outings into a funeral, but I also don’t want to drag the same broken bit around for six weeks out of principle. If something gets nothing twice in different rooms, do you park it for a while and come back with fresher eyes, or rewrite one clear thing and test it again straight away? I think my current system is either panic-edit immediately or become emotionally committed to proving the audience wrong, neither of which feels especially scientific.