How about ask one of the chosson’s friends to stand up and say all sorts of really bad stuff about the chosson. But at the end he’ll say “just kidding.”
The only appropriate entertainment would be a professional Badchan. Otherwise or in addition “make sure” the speakers are well prepared and not too boring. Warn all speakers to not start off their speech apologizing how unprepared or unqualified they are, because if they are then they shouldn’t be speaking. If they insist on speaking nonetheless and actually proclaim those silly disclaimers then they have just signaled most people to tune out.