Do it dry.
Zero need to use StarSan on a crusher.
BTW, I got rid of the Barley Crusher I had originally bought back in 2011 since it just wasn't really good enough to do the job. Went with a Monster Mill (original two roller version) with the 2" hardened steel rollers and haven't looked back. Serious upgrade from the first crusher I had.
At $50 you'll be OK for a while. Until you get frustrated with it and decide to spend the money for something significantly better.
BTW, Monster Mill is 100% USA made (made in the USA with USA made materials). IMO, that's a company (and product) that deserves our business. Especially with how much is "assembled in the USA from globally sourced parts" these days.