Chris - Why cant you put in water and/or a W.B. cleaner into the circulating tank for cleaning? Maybe something like a windex variant that doesn't foam up? (amonia based cleaner)
I assume the point is to capture w.b. ink particles for disposal?
For what it's worth, if an employee has left out a waterbase squeegee or utensil and its dried up, we put a little easyway 701 on a scrub pad and it comes right off.