Baking soda will neutralize acid, but you need to use enough of it to do a complete job. Mix it into a super saturated soloution (keep pouring powder and mixing in to water until the powder no longer disolves and piles up on the bottom) then rinse it several times, a soak for 15-30 minutes is even better. Once it's clean and dry again it will start to rust IMMEDIATELY so you'll need to treat it appropriately. I final treat all bare metal with Ospho before other coatings get used, it leaves a phosphate coating after a brief water rinse that will prevent flash rust for a few days while you prepare the parts for paint or whatever.