For the record, I've been told to never wash my belt for 3 reasons:
Originally posted by Erik
1. Ye olde white to brown to black to white story.
Myth. Urban legend (look up Peter Urban and his Tales of the Dojo for that reference)
2. It's tradition (not exactly the same as #1).
That's the only good reason not to wash it (unless you use a kaku obi, which should be handwashed very gently lest it disintigrate and turn into a limp span of shapeless wool).
3. Washing removes your ki from the belt.
So ... if you take a bath does you ki go down the drain?