As I said earlier. It's what I'm still using. The reptile bedding works well and for me, was no trouble to buy, firstly a small bag, to try out, then a large sack, from my local pet shop. But walnut blasting media, sieved to the optimal size, can be had for even less, if you look around.I use walnut media. however I found that the cheapest source is pet store suppliers. It is used for reptile bedding and bought as such is much cheaper than anything for Firearm use.
Paying for the firearms stuff at many times the price is perhaps convenient, but I am frugal, and don't think much of buying USA made profitable stuff, shipped over the pond, import duty perhaps, importer/distributor's cut, retailers' cut, none of which I begrudge, business is business.
But if I can mix up my own concoction, which is trivially easy and not a precise matter, for maybe 1/5 or 1/7 the cost, of course that's what I do. If I can fill up my tumbler twice, for say £4 rather than £20 or more, it's a no-brainer for me. I don't think that the commercial offerings are materially different, this is mature technology. Which still works.
I've maybe put at least ten thousand cases of my own through the tumbler based on how many primers I've used, and probably the same amount for friends who don't have their own tumbler, but I have done it for them, as a favour. This is far off the scale of what an average deer stalker/fox shooter/reloader might do in a lifetime.
FWIW I have tried ultrasonic, in a small way, certainly can get everything out, ten or 15 at a time in my little thing, , but does no polishing, and can leave the brass looking bad. Adding citric acid superficially helps, but then has to be neutralised. Even when done well, dried off straightaway, after a while it still tarnishes. A dry tumble can polish it up afterwards of course. Yet to try the SS pin (or other shapes) method but that seems to me to have merit. Actually Lyman nowadays say that I can use the small bowl of my Turbo Twin, with the lid on, to use e.g. SS pins or something else, maybe ceramic, in a wet vibratory method. Might give that a try, one day, if I find some cheap pins, or can scrounge a few handfuls of some other wet media, but not top of my priority list.

