Do you actually use them? We already have a pop up but I would love one with a bathroom so we could use it in the middle of the night and for a quick shower. Is it just wasted space in yours or do you use it?
Fill it with cat litter if you end up using it and drop it in the trash.
One thing about the pop ups is that most are casette toilets and you basically have to carry the jug to a cs or dump station. I'm thinking no way. I would get a porta potty just for emergencies. Fill it with cat litter if you end up using it and drop it in the trash.
Emptying the cassette sounds like a terrible task, when we got our pup we determined to not use the pottie in it much at all because of the perceived yuckiness of cleaning it. That did not even last the first night. To shorten the story I found emptying the cassette to be simple and painless. Pulled it out, rotated the spout, unscrewed the lid and dumped into the sewer line. Did not see it or smell it. Reinstalled in reverse order and pumped a few flushes of chemicals in and all was well. Took less than 5 min.
What tvengineer said.