I didn't use this until a few days ago. So far so good. I have a little more scrubbing to do under the rim.
Product works really good. No problems. Use them in all my toilets.
Got 3 of these for our new house. Haven't had to clean a toilet since I installed them.
I Received the product about a month ago and it has worked perfectly. Seems like it really does what they say, a little expensive but worth it.