To aid in preventing this...

Fuelproof the inside of the area your fuel tank is in and drill a hole in the belly of the aircraft below the tank. Watch for any fuel comming out that hole.

If you properly fuelproofed tha area, then you have a much easier time cleaning up the mess. (fuel soaked foam goes in the trash and wipe it out with a paper towel.) Its quick and easy to do. I used to do this to EVERY airplane. On my 4*40 I didn't do this to... I had a leak and ruined the aircraft. (so now I do them all again.)