Bamboo steamer baskets - cleaning

I have bamboo steamer baskets that I use primarily to make frozen dim sum, some of which have, since my last round of frozen dim sum making, become covered with a layer of dim sum drippings. Any suggestions on cleaning these? Obviously they don't go in the dishwasher. But can I wash them with soap at all or will they absorb it? How wet can they get? Presumably I'd be fine with washing them with a damp cloth (they do after all sit in a pot of steam during normal use) but can I dunk them in a sink of hot water?