I pull the senor assembly out every once and a while and use isopropyl alcohol on a q-tip. Remember it is an electronic sensor and not something gummed up like a carb. I've always felt carb cleaner was too caustic for use on the MAF.
It is worth cleaning every so often, I'll typically go through 2 qtips before I wipe clear.
I've also pulled my neg battery terminal when I do this to reset the ecu programming.