What do you mean by 'clean up'? Is that estimate based on anything? I don't think anyone is cleaning swamp coolers more than twice a year when connecting/disconnecting the water lines seasonally, I know I don't, not sure what that would mean with respect to the mediums since they have running water moving over them while in use anyway and it's either an accordioned cardboard thing or a mat of what looks like straw so it's not like you can scrub it without it coming apart. Never noticed mold. It isn't actually a damp enclosed space, they dry out very fast since evaporation is what they are designed for and they are open to the outside air.