For anyone who is still following this:
I got my ceramics (5/32 angle cut cylinders). I run some steel washers in them with commercial TSP spray diluted to 10% by distilled water. Although there was no flash rusting the washers tended to clump together which defeated the purpose of tumbling.
On the second run I added just a pea-sized amount of dishwashing liquid to
150 ml of the above solution in order to reduce the surface tension. There was foaming ++ but no increased pressure in the tumbler. The clumping was almost totally eliminated and no flash rusting either, in fact I left the dried washers out untreated and no rust for 24 hours.
The only concern is that the media is not aggressive enough for my purpose (it maybe that I made it too wet) but that is another issue.