Matt,
I think you Miss-Understood me, Its best that you wash the car with hot water Before anything is ever done with the car to make sure all is clean.

But you can still wipe your areas with the wax and grease remover then prime, But do not wash it with water now that you have started the body work , its to late for that.
After its all primed up and for final finish sanding you can water sand it with a hint of soap in the water and that will help clean the surface as you prep it for paint.

I think it might be in order to get a step by step process for you guys wanting to try your hand with Body and Paint work.

SprayTech