Im not sure how good the tissue would work because it would get really messy when wet and sand isn't a good choice because it can get caught in private parts. You can use papertowel though. I use papertowel in mine, I rip off two or three and leave them in the litter area and they are very absorbant. I change in the morning and all the mess gone
Sand is not good as Hedgieonboard has said. Lots of people use paper towels without any problems. Paper towels don't work with any of my gang because they just drag them into their sleeping quarters :roll: :lol: .