I haven't dipped coni's in Rustoleum but do us it on my DPs. I've been using the flat finish and I don't recall why I decided on it, but it works fine. I thin the paint down with mineral spirits which is what Rustoleum recommends when thinning. I try to get the mix thin enough that drips dry back and don't make little knobs to get knocked off. That means everything gets dipped at least twice to get good coverage. With the DPs some coon can strip all the paint on the first catch. I would think on coni's the paint would hold up well for quit some time except on contact points.
I do have a mix of coatings on my coni's tried over the years but I now dip most in steel coat.
Mac