Urinary health treats

Does anyone know if the urinary health treats or chews help also, just was wondering if anyone has tried any and if they help

 Do you have a cat prone to UTI's, or stones, or what?  I've read that if you have a cat prone to stones, and is on RX food, it's best NOT to feed it anything else, but that's just what I've heard.  Or are you just talking about something possibly with cranberries in it to "ward off" any possible future issues.  I've also heard that if you have a cat with KIDNEY issues, NOT to feed any treats with cranberries .  But, of course, kidney issues and UTIs are two different things.

My cat had a blockage from crystals, the ones that begin with S not sure of the spelling  I have him on canned food different brands since then. He would never eat the vet food. I was talking about the treats with cranberries in them to help keep his bladder healthy. He never had a UTI even with the blockage, I just was wondering if they were good to use?

Struvite crystals.  I'm just not sure. I'm going to ask that your question be moved over into the health forum, where it's more apt to be seen by people who've had cats with Struvite crystals.