Thanks for that info Tom. No more tap water...

You can usually find quite a few large capacity sonic cleaners on ebay that were surplussed from labs somewhere. Some of the them look good and are likely v high quality and are pennies on the dollar compared to their cost new. If there's an issue with using tapwater it may be because it's chlorinated city water maybe? Or softened water?? I use Dawn in my cleaner a lot but mostly for small parts. For actions I use lacquer thinner, which does an incredible job of degunking anything you put in it. I alternately run the cleaner and let it soak.

Very true John ,I have had this happen

Lyman's Turbo Clean has never had a negative effect on anything I've cleaned.
Lyman makes one for steel and one for brass. I think they make another also.
Cheers, Tom

Tom's right about the turbo clean and distilled water