Adhesion is an issue. Scotchbriting them fully before spraying would help.
I've seen some pretty decent results from aerosol, mainly this one via Gregg's
https://www.google.ca/search?q=Rust-Ole ... 80&bih=900Ooof, that was a link. If I could remember how to shorten it.. bah,
One problem is if the previous owner used tire shine, you'll have silicone enough to fish eye badly.
Black out wheels is not a fad I support.
Sometimes charcoal works- there's an Acura large SUV that has very shiny charcoal 19's in a simple, attractive design, my hands down favorite of the last few years. 19" and 5 on 120, neither of which fits any plans I will ever have, though I have considered asking the local refinishers to apply that finish to at least one other design.
When we send wheels out to have damage fixed on test drive cars it costs approx $165 ea for paint PLUS whatever welding or fill work they had to do, so I think home is about your only choice.