John,
The lacquer coating is supposed to be a rust protector for pipes used in sprinkler systems. We don't like it either. We always specify "black pipe" when ordering, so we don't have that problem.
Can't recall ever seeing where VIII and/or IX restricts the use of sandblasting or other cleaning method - but, then again, I wouldn't expect too. I think of VIII as a construction code only and I look elsewhere (ASTM) for workmanship, finish, etc. What do you mean by "other cleaning method"?
A108 says (paraphrasing here) that the material is to have a bright smooth finish obtained by cold drawing, rolling, or polishing. To me, that means no blasting is allowed. Anyway, if you were going to blast, I'd think the engineer would want to first see and approve your blasting procedure - I know I always do. And unless you can show me why you can't polish, we would never approve blasting. The fact that blasting is not an expensive cost factor for you is not a good reason.
Mr. Guilford is right on point regarding spatter sticking to blasted steel. Any savings you might realize by blasting will be more than swallowed up by the time and manpower needed to remove spatter.