Honestly I'd expect that to be SIGNIFICANTLY easier to waterproof than a laundry machine. Partly because laundry is sometimes done warm, and warm softens materials (like gaskets), but mostly because laundry has surfactants that considerably reduce surface tension, making it far easier to slip past gaps.

There is a good reason waterproofing claims are specific about the kind of liquid (usually just fresh or salt water, usually without significant movement (i.e. jets, like you get in a shower)).