Apron dance

These are commonly done in my area as well (northern WI/MN). I've been to ones that last 45 minutes because people will not leave the floor. I've also been to them when they last 5 minutes. Its awkward and usually the point when people sneak out of the reception. FH's brother did one and afterwards there were probably 15 people left (and that was at 9pm).

ETA: Corrections, because I apparently cannot speak the English.

Yes very common in Minnesota. In my area most guests only give like 20 in a card but give a lot more for the dance. Guests actually ask about it.

I have been to 3 Polish-American weddings in northeast PA that had dollar dances (money did not actually get pinned onto the couple).