SSMCJON.... a salesman you are. Now let me tell you what you just said. If you follow the directions to the letter, the company will return your money when the part rusts out.
A money back guarantee does little for someone that is working on a car that may be worth upwards of $100,000.00 when done. If the thing rusts because it was not repaired properly, the value drops alot more than the $25.00 that was paid for the POR. The product does have some good uses. If the wrought iron railings on my porch needed to be painted because it was rusting, that might be a good idea. Not much to loose, when it starts to rust again. It will not likely cost alot to repaint it later, and may last longer.
When I think of "lifetime" and "money back" guarantees, they remind me of Advance Auto Parts rebuilt starters. A few years ago, I had a repair shop. We had a customer that bought a starter from them, installed it himself, laying on his back in the gutter area of the street. The starter would not work, so he called me. I had the vehicle towed into the shop, and checked it out. The starter was bad. He said that he had a "lifetime" guarantee from Advance, so he wanted me to take it off, and he would return it for an exchange. I advised him that we would do the work for him, but if the new starter he supplied didn't work, he would have to pay again to have it taken back off. After the third starter was removed, he had me buy one from someone else, that way we were responsible for it. The one that I bought worked just fine, and he was on his way. It cost him more for the labor for installing and removing the starters, than the starter cost.
Guarantees like that, when they involve labor, are usually useless, as they usually don't cover the labor or related costs, or losses involved.