TAI is the industry standard for "fixing" or controlling fog in emulsions. Yes, you can repair overly fogged emulsions. TAI is superb as a pH 7.2 solution which we called NAZ (Sodium salt of TAI). A drop or so will reduce fog.
Benzotraizole and Phenyl Mercapto Tetrazole are good too (BTAZ and PMT) and both are stocked by the Formulary.
Last time I was out there, I made them a batch of TAI solution and they should have some for sale. I have no license to ship this stuff so get the chemistry from them. I am trying to build up a stock of emulsion chemistry with them and here at home. Those coming to workshops here can get the stuff from me as samples.