We moved into this house nearly 3 years ago. When we moved in, there were several black spots on the carpet in D's room (and not in a place I could place a piece of furniture either). I don't know what they were but they were awfully black so my guess was Sharpie marker.
I used a couple of different carpet cleaners to remove them with no luck. We had the carpets professionally cleaned with no luck so I figured they were going to be with us until we replaced the carpet.
Last week I decided to give the Norwex Carpet Stain Buster a try. I sprayed the spots, let them sit for 5 min and then used the Enviro Cloth to scrub. I repeated that process a couple of times and each time the spots got lighter and lighter.
You can barely see what was left of the biggest spot after 3 rounds with the Carpet Stain Buster and Enviro Cloth.
Next I got a Norwex Micro Hand Pad and scrubbed for a minute with that. Poof! Gone! I was so thrilled. I didn't think anything would remove those spots!