The trouble with slightly silly dances is that folks might not get that they are supposed to be humorous and instead find them embarassing. (or however you spell that)

I suggest you announce that "We will now rest our tired brains and do something absurdly simple..." such as

Here we go looby loo
The Chicken Dance
Jack on the Ball.

Such dances aren't all foolishness. You could work on posture, balance, style and showmanship while doing them. For example, in Looby Loo, when we 'turn ourselves about,' you could coach people to do it

like a ballet dancer
like a Highland dancer
like somebody doing the Charleston
like an Irish step dancer

I think it might be fun.