Purrley, I couldn't use anything except plexiglas under the litter box because my little calico, Patches, had kidney failure and was peeing outside of the box. A raffia mat would have been a disaster.

I usually keep a dust pan and brush right beside the litter box and clean up as needed.

I got the plexi from a plastics shop and they usually have leftovers that might work and not be as expensive as buying specially cut sheets. I use Windex and a paper towel to keep the back and bottom plexiglas clean.
I have wallpaper, so it is really a must for me.

Hope this helps.