sealers

Anybody ever hear of Adsil. I own a pressure washing company and I've been approached by several different guys who want to sell me expensive sealers. The latest guy seals roofs,ac units, driveways, you name it. He claims it will stop mold and algae for ten years. The stuff costs $160 gallon. I think it's gotta be bs but i'm trying to search around and find out. Anyone???

 

thx in advance,

Kevin