Use wire wool to scrub these clean with mild soap and water, ethyl alcohol or glass cleaner.
If you use acids (or emit acidic vapors) in a fume hood, then even stainless steel will rust or corrode.
A layer of wax can help to prevent this, but is also stripped by solvents and can make a steel surface slippery.
For wood or plastic bench tops, a thin veneer of silicone oil or wax keeps them shiny and easier to clean.