Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Amazing!!

I had a thumb sucker I never thought would ever quit. We used all over the counter nail polishes and nothing worked. We paid $75 for thumb guards which broke, caused sores and got strange looks as we went into public. This Mavala Stop, actually worked. Cured thumb sucker. I wish I would have gotten this long ago. My wife says only use a little though as she had a taste from using it to stop biting her nails....she is now growing nails out for the first time.