It is a chemical process where they phyically lift the body, submerge it into a caustic solution, leave it there for a period of time (sometimes overnight) and when it comes out you have bare metal. The paint, undercoating, and rust will all be gone. It gives you a totally clean substrate to start out with.

The E coating is essentially a special coating that is applied by immersing the body (or whatever parts you want done) into a bath and current is applied to the parts and the solution. The coating is drawn to the metal and will seek out every little space and cover it. I think some new cars are coming off the assembly line done this way.

As for who does it, they are becoming harder to find due to the EPA and hazardous chemicals that are used. Look in your local phone book or on line to see if there is someone in your area doing it. One company is Redi Strip, but others are also doing it.

Don