how to fix crosive stainless steel?
Answers:
You mean "corroded"stainless steel don't you. Are you sure it's SS? If you used a chlorine based bleach that was too strong you may be able to polish it out using a paste abrasive for stainless kitchen sinks. If that doesn't work you can always change the fitting.
Other answers:
While there are very expensive restoration processes that you can get done by pros off site, there are also some that are cheaper and that can be done on site by you. Go see your local hardware store for the latest product on the market, there are dozens of them. Choose one you can handle safely and do it. Some are as simple as painting the whole surface others require special equipment and techniques well within the average do it yourself-er.
While there are very expensive restoration processes that you can get done by pros off site, there are also some that are cheaper and that can be done on site by you. Go see your local hardware store for the latest product on the market, there are dozens of them. Choose one you can handle safely and do it. Some are as simple as painting the whole surface others require special equipment and techniques well within the average do it yourself-er.
All you need to do to Stainless Steel is use some toothpaste and buff it. that should put a shine on it.
You drain if it was shiny could be chromed brass or steel.
Stainless Steel should be cleaner proof.
If it did anything to SS you should not be handling the chemical.
If it is damaged the drain can be removed and a new one put in right from in the tub