Any decent interior cleaner will work but a very good all purpose cleaner is Bilt hamber surfex hd.
It can be used diluted for light cleaning and is a very good degreaser etc with stronger mixes.
A very handy product to have on your shelf.
I've used a wet carpet cleaner.
Spits water and then sucks it up, salt is diluted and stains become less noticeable.
To get rid completely use a upholstery shampoo (auto glim is good)