Ever gone walking around in the snow only to come home with weird white goo on your shoes? The white goo is salt deposits. Salt is poured on snow and ice to melt it so people don’t slip. But it makes kind of an ugly mess on shoes that will not dissolve when wiped with a rag dipped in plain water.
The way to remove these stains is to dip a cotton ball or Q-tip in vinegar and then to wipe the spot clean. Q-tips are nice because you can get down into the cracks where the sole meets the shoe. Cotton balls are nice for the top where they provide more coverage.
A product that works really well for leather is Horseman’s One Step. It is marketed to riders who use it on tack. It cleans and conditions at the same time, a necessity when leathers are out in the weather, getting wet and dirty. Pure oils make leather slippery and are really unnecessary more than once or twice a year. Lexol is good too, but it doesn’t clean unless you buy the cleaner separately. One Step does both. I used to clean dozens of saddles and bridles daily and One Step was my favorite. I highly recommend it. And I did not get paid to say this. I wish! After cleaning your shoes of salt, a quick swipe with the One Step makes the leather clean and supple again, ready to head out into wet, winter weather.