Try a small medium weight scrub brush, a little dish soap and water and that should take care of it. Then wipe it dry...first with the damp rag, then with a dry towel. I have done this with toms and snares. I understand why you want to clean them, if no one else does. Eventually they look like someone has wiped a bum with them, and they aren't always used up at that point. I use rubber PD-8's for various sounds/triggers, and when I have used coated heads in the past they get ugly after a time.
Thanks for the tip on the clear heads, to the poster that wrote that.