I brush Harleys teeth about once every other day simply bc he goes bonkers everytime I do it and therefore give him a break day in between each one. Anyway, lately there has been this yellow, hard, rough plaque buildup on his rear teeth and I've been brushing and picking and scratching at it (it's on the outside of opposite teeth) but it will NOT come off. I'm in the process of getting a metal dental scraper right now. I know a while ago there was a thread posted about this really great all natural spray/liquid for whitening and removing plaque from your dogs mouth. (it was so good and natural that the man who made it actually sprayed some in his own mouth to prove it on a video I watched) But I cannot for the life of me remember what it's called. I really want to order some to see if it will help my Harley. I will do anything to keep his teeth healthy bc I know healthy teeth are the first steps to a healthy dog.. PLEASE HELP!