I have a large (color coordinated of course) pool noodle stuffed up under the sink edge between it and the shower to help keep stuff from falling down and getting in there.
Donc13- I put Glad press and seal over the shower door track and drain when the litter box is in there. Helps keep the litter out.
For cleaning in between I have used different things like a long feather duster, sticking the DustBuster in as far as I can, Swiffers and whatever else I think up. The glass on the outside doesn't get wet just dusty and you can't see through it anyway! 🤷♀️ I'm pretty much a fanatic/germaphobe, but sometimes you can only do so much.