Make sure it is not cooked rice though hehe.... (use a few grains of dried, uncooked rice - it doesn't matter what sort).
I keep my salt in a little dark green glass jar with a cork bung on the windowsill near my cooker - I think the cork absorbs any excess moisture because the salt itself never gets damp. The rest of it stays in the cupboard in its original container. I find that keeping it with the teas, coffees, sugar, peanut butter, gravy powder, mustards, soya sauce, sesame oil etc etc tends to keep it out of trouble and dry.