The problem with dipping is it can remove rust from spots that you will never see. There are parts of the car that are protective coated while its being built that no one can ever get to again. Also dipping is very expensive and hard to find a place to get it done at anymore.
In a few years I may invest in a dustless blasting system to make a little extra money. The dry ice just evaporates all u have is a little water run off. Clean up is a breeze.
The dipping I looked into was a three part process that stripped and dissolved rust leaving the good metal, rinse dipped it, and then dipped it into a solution that was charged I believe to coat the metal with anticorosion material.
For what I spent on materials, industrial high volume compressor rental, time involved, cleanup,etc, plus a wife po'd at the entire process, having the car dipped would have been a bargain.
At the time, baking soda was the best method of blasting. Haven't heard of the dry ice. The lack of clean up would be appealing.