Would be willing to bet that if you use Caustic to maintain pH, you will
split the emulsion quickly.   Suggest using (diluted for easier pumping)
Monoethanolamine, with pH meter/controller set to just slightly below pH of
incoming cleaner.

Also, have a funny idea that used cleaner, pH adjusted, may clean better than
new stuff, at least until Rosin soaps build up to the point that they do not
rinse well.  And, incidently, this can be virtually completely avoided by
rinsing in deionized water.

Good luck

Rudy Sedlak
RD Chemical Company