I'm planning to do some sandblasting on my 52 Chevy truck (chasse, rims, & maybe the body). After doing some reading, it sounds like many of the blasting medias can cause health risks due to breathing silica, so I'm thinking about using fine (24 grit) walnut shells. Are the shells effective in striping rust & paint? Is there a different media that works better, without potential helth risks? Any thoughts would be appreciated. Thanks.