What is the best carpet shampoo/solution for the Rug Doctor type cleaners?

Question

What is the best carpet shampoo/solution for the Rug Doctor type cleaners?

Answer 1

I shampoo our carpets each spring with a Rug Doctor.

The (Rug Doctor) shampoo works wonders.

Do heavily soiled areas first, then continue with the rest of the room, then go over those areas again.  This gives the shampoo a little time to soak in and soften up the dirt.

If you've never used one before, you will gasp at how effective they are.  Look at the water when you empty the catch chamber.  EEWWWW!

Answer 2

Any steam cleaner. White Distilled Vinegar and Hot water!