I use plain tap water. Enough to fill the US cleaner to the right level - maybe 50-60 oz. A small squirt of regular Dawn dish soap - about 6-8 drops. Just a pinch of Lemishine - if some is good, more is better does not apply in this case. Too acidic & the brass will turn pinkish but adding none & the cases won't get as clean. You'll have to experiment to see how much a "pinch" is for you. I noticed that Speer and annealed military brass don't tolerate the higher concentrations of acid as well. Some others will take 2x as much Lemishine and not change color.
I run 3 8-min cycles and stir everything around between cycles (if stirring does anything beneficial I don't know).
Then I just rinse in plain tap water.
Others use distilled water and do another cycle with a baking soda solution to neutralize the acid. I don't and the brass will dull/darken a little pretty quickly afterward, but I tumble in walnut/car polish too so that takes care of it. If all you're doing is US cleaning, you will want to include the neutralizing step and maybe do the final rinse in something other than tap water depending on the mineral content & pH of yours.
So why bother when you can just tumble and get better looking cases? The US cleaner does a great job on the primer pockets. Other than to remove a crimp, I don't touch them. The US cleaner also cleans the inside of the case just about as well as it does the outside. Again, if there is any benefit to that, I don't know, but may as well.
What you DON'T want to use in your US cleaner is a lot of the jewelry cleaner made for US cleaners. At least not before checking to see if it has ammonia (many do & a lot don't say what's in them).
You can experiment around to find other things that work, but why reinvent the wheel? Water, some type of soap, and some type of acid is what you need. The Dawn & Lemishine is proven & lots of people use it with good results.
Also - don't put your wife's pearls or soft gemstones (like onyx) in the US cleaner even with jewelry cleaner - it will destroy them.