Best way to remove undercarriage coating?

I used a propane torch and a small scraper,then clean with lacquer thinner.
It is a lot of work. Also a lot of rags and use a small and large wire brush.
Do not use torch near the lacquer thinners (flammable). And dry the dirty
rags outside , spread apart before throwing them out.(spontaneous combustion).
Hope this helps you.
Darryl