If I was going to do that, I would get them sandblasted and power coated. Hot tank can be different chemicals for different things, know what chemicals are in the hot tank before soaking your parts. A hot tank at a auto machine shop does not remove rust. It is to remove grease, oils, and dirt. If it removed rust, it will also remove metal and you do not want that on machined surfaces. The hot tank may also require removal of all the control arm bushings, which you may want to replace anyways while you have the control arms out. Sandblasting and powered coating would not require the removal of the bushings.