As a permanent fixture, I imagine it to be like a toilet. It's always contaminated, but this can be dealt with similarly. The portable device, on the other ha

As a permanent fixture, I imagine it to be like a toilet. It's always contaminated, but this can be dealt with similarly. The portable device, on the other hand, has to be put somewhere. I guess you could have a "poop shelf" nearby that you always assume is about as clean as the bottom of a toilet seat. Actually traveling with that seems iffy, though.