Scratch'n'peck, I just now finished reading your thread - and some of Mr. King's replies elsewhere. Great, great stuff, all of it. I just wrote a reply to your post on SIMZS' thread, and I think it addresses some of your issues. Now that I know what you are looking for, I will elaborate here.
I HAVE administered Spinosid orally to young chickens. The product I used is Conserve SC, 11.6% Spinosid in propyleneglycol; it's a thick suspension that needs to be thoroughly shook before diluting to proper dosage, and it smells horrible. I purchased it from
Amazon, available only in industry sized quarts, which I thought pricey. (In the long run, however, this is a VERY concentrated product and will make many applications.). I used it to kill any fleas my young birds might have acquired from my dogs, and I fed it in doses recommended for dogs weighing the combined weights of my month old babies. I pulled the dosage chart off from one of the net sites for Comfortis (can't remember which right now). As I said in my post, I would have no qualms about using this product orally for chicken mites, but since my chicks didn't have mites, I can't personally assess how effective a MITICIDE it is. Others on your thread have been successful applying it as a spray, and I am delighted to learn that.
About the ORGANIC issue: Spinosid is the by-product of fermentation BY a soil bacteria, not the actual fermented bacteria itself. I think. Wikipedia was a little not too clear about this. Probably most of the stuff on the market is synthetically manufactured, which leads one to wonder just exactly how organic can it possibly be. Like permethrin, right? And ORGANIC may apply just to the labeled intended uses for a particular product, not necessarily for what and how YOU wish to use it. Mr. King says that one might contaminate or taint the meat or eggs merely by spraying the critters with Spinosid, so to be on the safe side it's better to toss the eggs and wait to butcher. What I'm suggesting is worse. I am recommending feeding chickens a once per month dose, so that the insecticide is systemic and lethal to mites which feed on them for the next 28 or 30 days. This will SURELY taint the meat and eggs. So, if your infestation is serious enough, if you don't like repeatedly spraying your coop and chickens as much as I do, if you want a great cure rate - orally administer the Spinosid in the winter, when laying is at a minimum and feed the tainted eggs back to the chickens. I would never sell eggs with traces of Spinosid; it may be harmless, but it's possible it could affect the flavor in a negative way. The non-toxic Spinosid I use has a very penetrating and strong odor and flavor, and it's conceivable to me that it could be tasted in the meat and eggs.
I didnt say it on my previous post, but I think I DID use the Conserve SC topically - in a bath and as a spray - for the box turtle with serious mites, the one that had a miraculous cure. Could have been the BZK, could have been the Spinosid. It is nice to have options. Like you, S&P, I wonder why Spinosid isn't better known to chicken lovers everywhere. Thank you for raising its conscious level where it needs to be risen. Hope this helps kindle the rising. Yours in Berthoud.