I wash my Astromomiks IR/UV filter in the sink with water just like it is a cup or plate.
I read on the net about how some people throw their Astronomiks filters in with the dishwashing!
I don't go quite that far, but even Astronomiks say they are pretty much indestructible and can be washed in a tub of water.
Explore Scientific have a new range of waterproof EP's that you wash in a tub of water!!!
From the Astronomiks website:"Furthermore the filters are very robust. You may try to clean them even with less than perfect cleaning methods without damaging them. While other filters might be scratched the Astronomik filters will still be in a perfect condition. Also, the filters do not age, you can use them for many years without them showing any less (or worse: more) than on the first night."
http://www.telescope-service.com/Ast...omikstart.html