shewhobikes, I wouldn't want to change a Diva cup in a porta-john, as I really, really need to wash my hands after dumping it out if I am at the heavy part of my cycle. I mean, scrub under my nails and everything. Hand sanitizer just wouldn't do it. And especially since you haven't been using one before, there is a learning curve (at least there was for me) inserting it and getting it seated properly, removing it, etc. -- you don't need that extra worry during your MS-150. With my luck, I'd drop it down into the hole, and then what!?
Emily