They have special products for doing stainless but it is not blueing.
https://www.brownells.com/gunsmith-tools-supplies/metal-prep-coloring/metal-bluing/bluing-salts/oxynate-no-84-hot-chemical-bluing-compound-prod1103.aspx
http://dulite.com/dulite_black_oxide.html
from https://www.thehighroad.org/index.php?threads/can-you-blue-a-stainless-gun.198151/
quote> There are two commercial formulas available to blacken and stain stainless steel. Brownell's Oxynate 84 and DuLite's 3-0 salts (which I use). Both are harder to use than straight blueing salts, but they will do the job. I use DuLite to blacken stainless and also for Win 94s between 2,700,000 and 5,024,957. It's also useful for those receivers with a higher silicone content that turn reddish or plum colored with regular blueing. <end quote