Scrub only after a long soak in a warm/hard water (at least 15 min), to soften the skin. No soaps, oils, or other products should be used in the tuba/shower prior to exfoliating. After the soaking you can start exfoliating your skin, use some pressure but not too much, it shouldn't cause pain. The washcloth will shrink after it gets wet, so don't freak out, it's normal :) Don't forget to use a moisturizer after, it will absorb it like a sponge!
Exfoliate your body just once a week, at most, and avoid the face. Supposedly you can use the pink one for your face, but I personally don't feel comfortable with that. I think even the softest one is still too harsh for face.
It makes your skin smooth and glowing, especially when repairing it after a long, dry winter. For me it's a huge help for my hands, as they have a tendency to get really dry, especially the part between a thumb and pointing finger - no idea why, I have since months, it keeps coming back. I used to put tones of moisturizer on that part of my hand but it didn't work that well. It took ages before my hands look normal again. With this washcloth it takes one exfoliation and the dryness is gone.
With regular use, it may help lessen ingrown hairs and it may help those with keratosis pilaris, which unfortunetly I have and I really do see a difference.
Another great thing about the washcloth is that it's reusable. Make sure to properly dry it after using. I let it dry and then wash it in washing machine on gently mode.
The same as with cosmetics and any other products, this method might not be suitable for you. You have to try it yourself and see how it works for your skin. Listen and observe your body, if it causes pain stop.