Spring, summer and fall i hang it all on the clothesline and really go at it with the hose, then into the wash. In winter I wait for spring.
If you have a septic field it would be a huge mistake to let clay get into it. That happened to a potter friend of mine. VERY expensive to fix that one (as in backhoe and plumber combined expensive). Sludge eating bacteria additives won't help.
I don't have running water in my studio so it's buckets hauled from the house in winter or hose filled buckets the rest of the year. You learn really fast how to conserve water when you have to haul it. So I clean my hands in the wheel bucket and rinse in a bigger bucket. The bigger bucket can go for weeks without changing since the clay sinks to the bottom. An apron is the order of the day (unless I forget). Buckets get dumped outside when they need to be cleaned up.