Would some solution of 91% isopropyl alcohol and water be a good sanitizer? The alcohol would speed the drying of the solution and the stuff is cheap at Walmart. If my thinking is correct, 91% alcohol has 29.12 ounces of pure alcohol in a total solution of 32 ounces. You'd have a 4.35% solution of alcohol in five gallons of water plus the 29.12 ounces of pure alcohol: 29.12/669.12 = 0.0435. If that's too low a concentration, we can go to four gallons. That would make a solution of 5.38 percent.
I have to ask: If alcohol can kill the type of bacteria we want to kill, why do we not use it instead of StarSan or any of the other brewery washes available? Maybe it just isn't powerful enough?