You know how it is: You buy a piece of glass, no mention of damage. It arrives. Seller does not respond to queries.
You have a fine/desirable piece of glass, but with waterstaining/iridisation on your glass. Do you get philosophical and think; "Ooooh, what a opportunity to try out preparation X, (X, I said, concentrate, Corporal Jones), and if that fails, substance Y (white crystalline, mildly corrosive (Vim, what else did you think I meant)) or some marvellous spherical objects, (prefer a nice Calvados myself) to gently swirl round inside the glass, in the hope all your troubles will just disappear?
Or is it better just to go " oh happy day", and sling item in the bin?
Go on, who has a proven method to save me from despondency???
Mod: This thread has information on chemicals to try to remove water damage, all of which is repeated elsewhere, but also has snippets of info about Sklo Union at the end.