I haven't tried it, but Chris Turner tells me that just sticking it
in one of those huge laundromat washers will do the trick.  Take the
foam rubber cushion out, of course.

-Karl

Karl and Kristina Bloss, Trexlertown, PA
'87 GL Weekender  "Beverley"
VW shop list: http://www.enter.net/~bloss/vw/vwshops