I get the bulk of the root ball out when harvest is complete. The little root pieces I don't worry about.
I soak the hydroton in a tote with a cup of bleach to each gallon of water, usually use five gallons. I soak anywhere from 24-72 hrs depending on schedule.
I have another tote with holes drilled all over the sides and bottom. Outside I dump the hydroton into this tote to drain and dry. Then hit the hydroton with the hose, stirring with my hand until rinsed well. Let dry.
Once dry into clean tote it goes with Hygrozyme 6ml/gal water pH'd to 5.8 for a couple days and then it is ready to reuse.