I've heard you can soak a towel in saltwater and wrap in around the head and let it sit.  I've never tried it but i've heard it works well.

The Tour Chrome finish will not rust.  Oil Can and Wedgeworks Black Oxide are the only available finishes that will rust. 

I have satin finish SM4's, went to the driving range in the rain the other day and put the neoprene club glove after i was done and left over night, tada, magically rust spots on the wedge face. Not the look i was going for, i typically wash after every use.

So what is the purpose of making the club rusty?  Is it like dings, dents, worn paint and varnish on a guitar making it have character?

Some people like the look of it because it doesn't glare.  And some people think you get more spin with the rust.

what is the purpose of letting them rust...i have the oilcan finish and they have already started to rust. is this a good thing?