What is the best DIY solution for cleaning stained carpets?

Shaving cream

https://www.hometalk.com/diy/clean/carpet/how-to-remove-difficult-stains-from-a-carpet-41722085

How to Remove Difficult Stains From A Carpet

This might be helpful

https://www.hometalk.com/diy/clean/carpet/how-to-remove-pet-stains-from-carpet-1923414

Hello, Have you tried the Oxi type carpet cleaners- I found them very successful in many of my carpet stain situations. We also use a rug doctor.

I use Spot Shot spray for smaller stains - it is simply the best.

For large areas, I use Awesome Orange oxygenated powder (from Dollar Tree or Amazon) mixed with water on a clean t-shirt.

I also use the Awesome Orange powder mixed with water in the canister of my Bissel Steam Cleaner (instead of the commercial carpet shampoo)--- it works so much better and so much cheaper!