For what it's worth, I just asked this question of the owner of SPI where I get my epoxy from. My concern was if there is the same problem using washing soda (which is baked baking soda)in the electrolysis process as with soda blasting.
He told me not to worry they react with the metal differently and Washing soda is safe to use (with SPI epoxy) though it might still be a good idea to wash with a bit of Dawn and water followed by wax and grease remover prior to paint.

He also told me in the past to make sure to remove any acid while its still wet. If it is allowed to dry to reapply the acid (phosphoric in my case) and let it reactivate the residue in the pores of the metal then wash/neutralize with plenty water.
I followed that with a shop vac blow dry to minimized flash rust which worked well in my situation. (no rust even after three days in the enclosed garage.)

Give me ambiguity
or give me something else