I may just be a huge slob, but all of my efforts to thoroughly clean things around the house usually creates sprays and splashes. Unless I've been cleaning bathrooms and kichens and empty fishtanks wrong all my adult life?
It can be aerosolized, yes. Same way that gut bacteria like E. coli briefly can be, once you flush the toilet. Incineration really does make sense, because of the concerns related to correctly handling the contaminated materials on their way to the wash (ie, incineration is not necessary, but IS simpler to do correctly. Also, it's cheaper).