Thats good to know, even soda blasting only lasts about 2 weeks around here with the humidity during the Summer.
I have been using a new (or different, might not be new) process lately. They call it a sand bed tank, it has sand in a liquid solution that heats up to 700+ degrees and removes paint and rust. I was nervous at first about warpage from the heat, but it heats everything up evenly with no problems. Alot of my students and friends have been using it. After the sand bed it goes into a tank of acid to eat ALL the rust off then into a neutralizer tank which leaves a coating on the metal that lasts for months (It needs to be washed off before priming).
This process removes EVERYTHING including paint, sealers and the dampening materials between the inner and outter layers of the hood and doors so they will need to be replaced.
It works great on gas tanks too, I have a motorcycle tank and frame getting done right now.