Not sure where else I might post this question so I will start with this. I am working with several small pieces 3" disks that are 5/16" thick. They come from a shop that will laser cut to size from plate but the outside edge as well as both flat surfaces have mill scale as well as spots that are moderately rusted (not really pitted, but rusted just the same). Up to this point, I have put on the lathe and used #36 sanding to knock off the glaze left from the laser cut and then use the lathe to finish off the edge. I have read several articles about pickling and electrolysis and I think that pickling is the route I will go. The question I have is whether or not I would be able to use a pickling solution like the toilet bowl cleaners or Limeaway in an ultrasonic bath with a stainless tank. I use a citric based cleaner for other projects and this will work on the rust spots on these disks, but would take forever to clean up the mill scale. Obviously I don't want to damage the stainless tank, but I would really like to speed up the de-scaling process by using the ultrasonic action. Any suggestions?