Previous owner of our boat used Cetol on the teak
swim ladder treads, but neglected to remove them from the stainless ladder to do so. The result was a grungy looking ladder. We had good luck cleaning
it off by first liberally wiping with acetone to soften it, then cleaning/polishing with Barkeeper's Friend (I buy the liquid in the plastic bottle - keeps better than the powder in a paper can).
It looks so good that somebody is going to end up doing all of the stainless rails and stanchions...