Apply a texture (like dirt or infestation) from the feet up

Hello Everyone,

i would like our character to look dirty or infested when specific gameplay events happen. It should be building up from the feet to his head, but unfortunately the UVs aren’t set up this way. Also the effect should be applicable to various different characters in the game. So I’m looking for the best way to do this. I’m thinking about using decals, could this be a good way to do it?

Any suggestions?