In my old shop, I put 2 heavy coats of Porter premium exterior gloss on the sheetrock walls around my dirty work area, (engine teardowns and ****** work, with a sand blast cabinet in the corner) over hopper gun spray texture orange peel. I added a biocide (mildew stopper) to the texture, the sealer and both coats of paint 'cause I live in the swamp. (the shop dawg molds if he don't keep moving)
when it got nasty, I sponge mopped it with simple green and it looked brand new.
The new shop will get the same paint, over hardi-board siding, bonded to the sealed block, and I'm adding FRP panels (shower board) 4 feet up from the baseboard, to stop the back edge of my rolling workbenches from scraping up the walls, call it a lesson learned. LOL RED