I've read a hundred posts about wet sanding. The one thing I didn't read was how you know when to switch from 800 to 1000 to 1200 to 1500 etc...? My biggest fear is going too deep and really screwing it up. I've already played around in a few spots. What do you do with the milky oxidation as your sanding it? Do you keep a hose in one hand and spray off continuously? Wipe it with a rag? Thanks for the help!