I was unsuccessful in proving that chloride alone caused etching of aluminum parts, there might be an interaction, or there might be some metallurgical reason why, in the same tank load, we had some parts destroyed by etching, and the others without a trace of a problem. But I can tell you this, in almost every case, the etching started in a blind, threaded hole. We used to wash out the holes with a jet of water, but I am not sure how effective it was. Once the etching started, there was no stopping it. The Canning Handbook gives chloride limits for anodizing solutions similar to the ones we used at Bendix, since you were looking for references.
Most references recommend using DI water in a minimum of the anodizing tank and the seal tank.
Most places will use it in as many tanks as they can afford. Avoid the whole mess, use DI and avoid the problems. Your sister company ,PWA has some limits, but I will question where they got them from. James, but nobody runs a DI unit without some limits on the purity, I suppose we are trying to determine that limit. And like documentation, its better to have wrong documentation than no documentation, at least you have a target.