Rust prevention for the bathroom

We're moving into our first house and find ourselves needing a whole lot of stuff!  My daughter found this shower caddy for the bathroom she will be using.  She really likes it, and the price is right but I can tell by just looking at it that it will rust in no time.  I'm looking for the best rust preventative product, in a clear spray, that I can use to at least defer this caddy from rusting in the shower.  I did a google search but - wow! - there's a lot of product our there - including several from Rustoleum brands.  Which one is best for my project?  Thank you in advance!!