I blasted the first scope I did: wouldn't recommend it. Sand gets in everywhere you don't want it. To be honest, I don't think an anodized scope needs much prep work other than degreasing. Sand it by hand if you feel the need.
I degrease, mask out any markings, hand sand and coat. I usually go with Duracoat for the finish. I could use the air cure Cerakote but I think it is comperable to the Duracoat. Definately don't use the bake on Cerakote.
Don't really want to bake a scope.