For small amounts of hydroton we use a 5 gallon bucket with about 100 holes in it. We put the bucket with holes in another without holes to soak in the chlorine tap water. Then lift out and rinse and repeat.

For large amounts of hydroton like ebb and flow or gro we use one of those small electric cement mixers from slowes. It has a couple of hundred small 3/8 inch holes drilled all over. Turn it on and wash away. This method washes away more of the nutrient salt buildup than any other way.

All buckets and tubs are washed out with a physan20 solution and pumped out through the drain to keep it clean too.

Did I forget to mention that large amouts of medicine are need after every step.