Most just use a dish soap spray(or diy/store bought fruit rinser), and let it sit for a minute or three, and then rinse in the bath tub. Either dunking it upside down in a bucket, or using the shower head.
As for dirt, anything goes as long as its pure dirt. some have bits of syrofoam, some have crystals or balls for hydration, some have time release fertilizer.
Its a potho so technically you could just rinse off all the dirt and repot.
And most put a layer of largish (too big to swallow) stone on top of the dirt. This keeps the chameleon from eating the dirt, and keeps the crickets etc from laying eggs in the dirt.