in reality, it's impossible to get out all the acid 100% , so there is a good chance that years down the road you'll have rust in unusual places where acid just couldn't be neutralized,I'd preffer blasting, litle sand can't cause as much damage as acid,even if it's damp,
If you ever seen any late model cars torn down and sheetmetal removed,they have some rust forming in tight areas, just recently I was working on a door shell of couple year old Mustang,the skin came off the shell and there was alot of surface rust on the bottom edge where it folds and you know if it got dipped,acid would never been washed out or neutralized out of there, just imagine how many tight areas are thruout the whole car