Got my two dual Harbor Freight Tumblers in.
First thing I did was give them a go over;
1: Got rid of the stock belt and used rubber O-rings. I can't say what size they were, but take a belt to a place that has O-rings and match it up.
2: Replaced the clear tube they have over rollers with soft red airline hose, it gives much better traction. I used 3M 77 spray glue to bond them.
3: lubed the bushings with light oil.
4:
Light coat of silicone grease on tub seals.
I placed 100 (13.4 oz.) 9mm cases in each tub and 1lb of pins.
I mixed up a solution of 3Qts warm water with 1/2 tsp. of HF Tide cold water laundry detergent and 1/2 tsp. of citric acid (Lemishine, Vanish..Etc..)
I filled each tub up to just over the brass and pins. I made lots of solution due to having a ton of brass to clean.
Sealed them up (don't forget to burp the tubs before sealing) and placed them on the tumbled for 3 hrs.
Here is what they look like side by side to a previously sonic cleaned.
I think it is safe to say, I may have been off on the original quantity of brass I could fit into each tub, but the results speak for themselves. I am happy with 400 ultra clean brass every 3ish hours.