Trail Shoes

What are you supposed to do about the mud on your trail shoes? I mean, are you supposed to clean them off some in between runs or just let them be? My shoes have less than 40 miles on them but you sure wouldn't be able to tell from looking! It seems silly, but I am thinking that maybe you are supposed to brush the mud off them. I have heard that the mud can affect the performance of the Gore-tex. And we wouldn't want that! Especially if I have to wade through any little creeks. Hmmm, maybe I will try that after they dry out. Also, right now it doesn't look like there is much mud on the shoe laces, but I tell you, when I have to tie them it definitely is not like tying a regular pair of running shoes. Laces are very... stiff.