I use a Bissell Little Green Machine on my interior stains (even on the headliner). But for the nasty stains I still resort to a carpet cleaner, brush and a strong Shop Vac. I mix up a bottle of the Oxy Paste stuff and water and that has been sufficient for my tuff interior stains. Except when the dog has accidents in the Explorer then I break out the pet cleaner with odor removers in it (called Out I think).