How can I get a Fluid.app SSB to go back using a two finger swipe? When using Firefox and Safari, I have become accustomed to using a two-finger gesture to go backwards or forwards. 

It's a drag that I can't get this to work on my Fluid.app SSBs. 

Does anyone know a way?
I use the BetterTouch Tool application to handle two-finger swipe gestures with my Fluid SSBs. It works for me but you do have to set it up for each SSB, not just Fluid itself. Thankfully there is a copy gestures option.