I suddenly "noticed" about 20 years of embedded dirt in this back shelf
I'll bet I've put about six or seven applications of this commercial carpet foam for car carpets
And I learned you really need a nylon brush to work the foam in to the carpet

 it seems to get it out but slowly but another hint I picked up on the net when you're wiping it off with a clean rag don't go back-and-forth because you're just pushing more dirt in
One swipe down with a clean Terry towel
I notice it is picking up dirt on the towel  but I may start seeing where I can get this whole thing steam cleaned 

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