Do you keep the line that gets a laugh if it pulls the bit in the wrong direction?

I’m trying to get less sentimental about lines that work. Sometimes a throwaway gets a decent laugh but suddenly the audience thinks the bit is about something I don’t actually want to explore, so the next thirty seconds become me dragging them back to the original premise. Do you keep a reliable laugh and rewrite the route after it, or cut it if it keeps teaching the audience to expect the wrong thing? I’m starting to think “funny” and “useful to this bit” are annoyingly separate tests.