So. A sort of Folk-Swingers night is planned, huh?
Swapping is not just harmless fun you know, all sorts of problems may arise.
Next thing you know, swapping with other folk clubs will not be enough.
Blues or even Heavy Metal may get involved, then its only a slow downhill progression to.....................Rap !!!
I think a visit to your nearest confidential Folk Guidance Councillor would be your best and safest option.