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

The ChemFree product is a great for keeping the toilet bowl clean. I began using these many years ago. We recently moved and, when the plumbers had to be called in to clear out the clogged up pipes, they pointed out a chemical product in the toilet tank. They told us that those cleaner tabs would corrode the plumbing fixtures. So, it's nothing but ChemFree for me!