For a waz I just use a boab. Quick shoulder check and slosh it out under the van. I have a weak bladder, always have so I probably have a slash 4 or 5 times a day.
As for a dump, only been caught short twice I keep a carrier bag and some pot roll in the van for those occasions. Just crouch in the back, drop my guts in the bag and tie it up. Not telling you where I've slung it.
That really is disgusting mate...what an animal!
Probably more sanitary than using public toilets thats covered in flies, poop, urine, jizz, sweat and covid.