I tried to find a pciture of one, but seeing I only know the Finnish slang word for the cup, and tried looking from Google Picture search with "ass cleaning cup" etc. I was not very pleased with the picture results and want to go cry in the corner.
But yes, basically you have a cup that you place around your asshole and then swirl it around so everything comes loose, then you carefully open it so the crap and water spills down the toilet and if you're good at it, that's all it takes, clean ass! No need to touch any feces, but if you want you can finish it with a few splashes to be on the safe side, the times I've tried it I didn't have to, but I did check with a sheet of paper to see that it was all clean - still, one sheet of paper vs. a literal shitload of paper wins in my book.
I'll try to get a picture of my friend's swish cup if possible.