One thing I’ve learned about soap is that it always leaks out of the container. Probably more so when going through drastic elevation changes like my popup camper often does. An easy solution is to store all of these items inside a plastic container and place that container inside the sink pan.
Of course we travel with the container closed.
A container like this also allows you to move these smelly items to your vehicle to prevent a bear or other wild animal from trying to explore inside your popup camper! We use the Sterilite brand.
For other plastic container storage ideas, see the “Plastic Drawer Cart” post.