6gun - I sold a Hornady Sonic Cleaner (the newer one that looks like a metal box) before I moved. I'll buy another in a little while. I liked mine, but yes, they don't work like the youtube videos show.
I cleaned rifle and pistol brass in mine, and I used the Hornady liquid that they market, along with distilled water. That juice lasts for a whole lot of cartridge cases.
One thing I learned early on: the cases right over the transducers get clean the fastest. Since I would fire up the unit in the evenings when I was working on the computer I would regularly get up and take out the ones that were clean, rinse them in fresh water, then dry them, and then move the other cases right over those transducers. That worked the best for me.
This is too much work for a lot of people and I understand that there were many folks who thought the sonic cleaners were misrepresented. They might have a point, but I loved the way my cases came out, as long as I was willing to kind of babysit the cleaning a bit.
I warmed the solution up to about 120 degrees; that seems to help too. And once my cases were all cleaned, rinsed, and dried, they went into the corn cob in the vibratory tumbler. (Sometimes nickel plated pistol brass would show spots, even when rinsed right away after coming out of the sonic cleaner. The corn cob and the vibratory tumbler would get those funny looking spots out completely). Again, this is way more than a lot of folks want to bother with, but I have always been in love with really clean brass. Hope this helps. - DixieBoy