How do I clean cum off of a mouse mat?
At least I think that is.
You need something that dissolves the material semen is made of. Water will only cause it to get more dirty. Ethanol / Isopropanol will not dissolve it well and might damage the mat.
Acetone and Ethyl Acetate are really good at dissolving biological material. You could use the solvents in hairspray but you'll need to whipe quickly so you don't leave residue, you don't have this issue with the liquids.