I had to laugh when I opened my mail to read how one reader was able to get his glass shower doors so clean and sparkly that they looked like new. I had a can of his remedy sitting right there next to my computer. Hold on! That can of WD-40 was not there to be used as a computer screen cleaner. I’ve never tried it, do not intend to, and hope you do not either. There is a much better way to do that. It was on my desk because I had just used it to test the theory that WD-40 would waterproof my leather boots. Supposedly, WD-40 acts as a barrier so moisture can’t seep into your shoes and get your socks wet. Dear Mary: We bought a home not long ago, and the glass shower doors were so badly stained I actually thought the glass had become …