is it ok to soak the nickel plated brass kettle valves from brewer's edge in star stan?
Get rid of the nickel plated sissy pistol and get one of these:
As you know, Star San is acidic so if it can get under the nickel it'll start a corrosion process between the nickel and the brass. Of course on the up side the Star San will most likely strip any lead away too.
spritz it, No need to soak it. But, as you said it's on your boil kettle, so it's going to get pasteurized every time anyway- yes?
If you can take it off and soak it then, Why not drop it in a pot of boiling water? That'll do you the added service of stripping organic crud away. Star San is not a cleanser.