It is true what you have stated and what the others have said. But I'm pretty sure the Tein SS (and the HA that they are based off of) are steel bodied. So, yeah, they rust.

If you have the newer SS (I think almost all of them supposedly came this way for the US market) they should have a teflon coating or something of the sort. You'll probably be ok. Otherwise, people used to periodically spray the exposed threads with WD-40 or oil.

HTH.