Good step forward. Our emulsion making was fully automated as you describe. So, I am used to it!

Congo Red can be used for the Dye Bleach process as an imaging dye, but it is not a sensitizing dye at all. Compare the structure of it with those in Mees or Mees and James. You will see that Congo Red is an Azo dye, where as sensitizing dyes are mainly Cyanine, Merocyanine or Carbocyanine dyes. The number of C=C bonds in the chain determine the region of the spectrum in which the sensitizing dye operates.