BestAir HumidiClean All Evaporative Type Humidifiers Single Piece, 32 fl oz

This product, while a bit pricey, is solid. I put in just enough to cover the bottom of the tank and leave it to soak. An hour or so later it i fill it all the way with hot watter, then 20min later rinse and wipe clean. I've also used it to clean bottoms of sinks and nozzles (using a rubber band and a small cup). Obviously requires soaking for great results but once cleaned %26 rinsed, there's no chemical smell of any sort and that is the goal.