has any one tried using a little methanol or nitro (or both) mixed with their standard gas mix?

Most gas burners can be run on methanol with some oil mixed in, IF and only if, you rejet the carb as it takes a tremendous amount of methanol to get the power out of the engine. The jets for gas are much smaller and will not pass enough methanol.

I mean only a couple of percent of each (nitro and or methanol) with the gasoline.

Make sure your carb seals can handle the alcohol without damage