I found a guy in Vegas that does "dustless" blasting. Its crushed glass and water. Works great, does not warp panels. Last step is he washes the job down with a rust inhibitor.
Now, don't believe a dang thing about "dustless" He did it in my BIL driveway in Vegas and I gave the next door lady 20 bucks to take her car through the car wash, it was covered in dust.
http://www.cleanworksblasting.com/
He bought his system from:
http://dustlessblasting.com/
So, find a dustless blasting business in your area....give it a try. He did my whole front clip and trunk for 300 Bucks. The crap you see under my car is the "Dust" crushed glass.