ScalpmasterShampoo Brush, Purple

Q: I am middle aged and want to stop hair loss. When I scrape my scalp with my nail I see a dry white residue. Will this help me?

The white residue could very well be shampoo or hair product build up. I found this article interesting: http://www.healthguidance.org/entry/14574/1/How-to-Remove-Buildup-From-Hair.html

Q: Is this brush a hard plastic, or is it rubber?

It's hard plastic, but with flexible bristles

Q: does the finger loop tend to come off?

we have 3, and none of the loops have come off as of yet.

Q: What does this brush exactly do? Can I use it over and again? Does it work for dandruff?

yes you can use it multiple times because it is made of plastic. Yes it does work for dandruff. I have really bad, flaky scalp and it cleans my scalp really well.