When I first bought rez block years ago I don't think I used it right. Cause with my new water piece it's so easy to tell when I do and do not use rez block. Rez block just does what it's name says it does. It blocks resin from building up. For me it's most noticeable on the downstem. You don't have the black build up on the outside or inside of the stem where it's submerged in water. Makes cleaning that much easier, it's a bit pricey in my opinion, but if you do something well never do it for free.
This is the only stuff I put in my bong, you have to it every three to for days. It does an amazing job on keeping all your glass clean.
I love how it keeps my glass pieces clean and easy to clean.
wonderful great stuff, bring back smoke soap!