The way I look at it is that I have enough trouble coating the bottom of a frying pan with hot oil when I can see what I’m doing. I can’t imagine being able to get anywhere close to complete coverage trying to coat the inside of tubes essentially blind. My guess is all one can get by using such a product is a false sense of security when no security is needed in the first place. My 40 year old steel bike has commuted in the rain, toured in the rain, been stored in a carport, a basement and now a garage and it is still going strong. And while in San Diego now it lived for 13 years in humid St. Louis. I have chosen to save my $ and my time and it is a frame that is very dear to me, not a beater.