Homebrew PCBs

Ive heard a few different opinions about the finish of the copper
surface before etching.

One theory suggest that its better to have the surface slighly rough
because it allows the resist layer to grip it better.

The other theory suggest that its better to have a perfectly smooth
surface.

My only evidence is my few successful attempts at etching using PnP. I
used a 320grit 3m sanding block to shine and rough the surface before
etching and the PnP seemed to adhere very will except in a few places
where either I did not have enough toner applied or I did not have
enough heat and pressure  applied.

Im going to try using a chemical remover but the question is how do I
remove the residue from the chemicals. If I rinse it with water
wouldnt that start the oxidation process quicker than leaving the
board dry?

Regards
Wag