I once worked in the commercial plumbing industry, for a manufacturer's rep. Had to learn a bit about various specialty drains. Many of the specialty drains were available in stainless steel. The standard was type 304, which is pretty good stuff. Much better at resisting corrosion than the stuff that's used for decorative stuff, like automotive grills or the cheaper exhaust systems. (Yes, there's more than one kind used for exhaust systems.)
A few were available in type 316, which is sometimes called, "medical grade". This was specified for use in places like battery rooms (think forklift charging) where they might be exposed to sulfuric acid, or for labs where they might encounter all kinds of nasty corrosives, including.....
Deionized water.
Stick with distilled.