Blasting Media, walnut shell or aluminum oxide?

[big-b]

I want to strip the paint off my body panels and i'm not sure what to use. I have access to good blasting equipment but i have to by the media. I thought walnut shell was the way to go but the guy at Harborfreight says the 24 grit walnut that they have and list as fine is actually pretty course. Everything i've read suggests he might not know what he's talking about. He recommended 70 grit Aluminum Oxide. Most of the paint has been sanded off with 220 grit and a DA snaded i am just blasting the areas i couldn't sand and the insides of the parts. What do you recommend?

Brian