Painting inside of frame rails

The Eastwood internal frame coating works great. My shop is near a high end restoration shop that I hang out at a bit. They use that stuff all the time. After they dip the frame they use it. I've actually seen it used and they rave about the results. For hobbyists they say it works great on undipped stuff too. Just blow out the loose stuff and spray away. They've also mentioned it for trunk extensions, inside doors, or anywhere else that's not practical for Joe public to prep right.