Aurora makes a bottom wax with antifouling capabilities. It does work as a real basic anti fouling, as I use it all the time when I am in the water for extended periods, usually at 2 wk intervals (Bahamas or Keys). It's not a long lasting solution, but I have found it to work.
I cannot support any claims as to the speed and fuel improvements as posted by the manufacturer. http://www.auroramarine.com/