There are of course some store-bought remedies for cleaning magnesium chloride from vehicles. Some will depend on what part of the car you are intending on cleaning, but others it doesn't matter. There are some chemical ingredients in these to remove the magnesium chloride and to prevent any damage to the vehicle.
One such line of products includes Mag Wash. This product and others from the same manufacturer will remove the substance without damaging paint, chrome, aluminum or any other section of the vehicle. It is easy to use, but you should read the instructions before using and wear rubber gloves while washing the vehicle.
Home Remedy for Cleaning
For magnesium chloride stains, you can mix one part vinegar and one part water. You can either apply it with a sponge or with a spray bottle and put the solution directly onto the stains. Then dry the spot with a dry, clean towel. This also works for clothing, but you will need to soak the articles in the solution overnight. In the morning, you can rinse it with cold water. If the stain is still there, then you can repeat the process until it is gone.
If you have a hard surface that is stained, then you can mix equals parts of flour, vinegar and regular salt into a paste and rub it into the surface. Leave it to sit there for an hour before removing it with brush. Proceed to buff the spot to give it a shine matching the rest of the surface.
Home Remedy for Cleaning Chrome
The first remedy you can try is scrubbing the stain with simply cold soapy water with a brush. You should use firm, circular strokes while cleaning. To rinse, use cold water, and then dry the chrome with a lint-free cloth.
You can also use oxalic acid to remove the stain. You will need to use a gauze pad with just a bit of the acid added to it, and blot the stain. Once the stain has been removed, you can rinse off the chrome with cold water, and again dry it with the lint-free cloth.