The Dollar Dance, like its name, is outdated.  What you are doing is telling all the people enjoying themselves on the dance floor to stop having fun, sit down, and give you some more money.  Your reception is already going to seem short, the result of doing the Dollar Dance is that you have brought the party to a stop for 15 minutes or more, and expecting more money from the people who gave up a Saturday night, bought a present, and who were having a good time.
As you can guess, I think is not a good idea to continue the tradition of the Dollar Dance.  There are much better ways to take a moment and talk with guests.  If you are going to have the Dollar Dance, make sure the people collecting the money (typically the Best Man and Maid of Honor) keep the line moving.  I recommend about 15 seconds for each person.  It sounds short, but it reinforces that each person only has a short time.  The people collecting the money will let them dance longer, so it is better to have them thinking a short time.  30 people getting 30 seconds each will result in a 15 minute block where no one else is dancing, just waiting for the party to start again.