Most shops will do doubles. You just have to ask and be prepared to empty your wallet quickly. Get the girl to choose who she does the double with or else you are doomed to failure if you pick two girls that don't like each other.

The best doubles are amongst my best punting experiences, the worst ones are twice as bad as a bad punt as you are paying twice as much for a bad experience. Very hit and miss.

I have done 6 doubles. Three were amazing, two were ok, one was shit.