I have always used CLR when the shower head would get all gunked up with calcium but those were the plastic type shower heads. Can you use CLR on satin nickle?
I don't see why it wouldn't work. I use CLR all the time the only problem I have had with it is it bleached my formica counter top when I set the bottle down left a nice ring imprint.
must clarify I do not have nickel fixtures yet installing tomorrow. I don't know if I would soak the whole thing just in case as I just opened the kitchen tap box and it says don't use corrosive cleaners I would still use CLR but carefully. Hope I didn't lead you too far astray.
I would look to the manufacturer to see what they recommend, since different makers create that finish in very different ways.