Peepinator-
I really do hope someone chimes in on your post, as I am obviously the wrong person to advise you. I too have spent the last couple of days in total freak out mode trying to figure out how best to approach my own chicken situation. I don't have any little peeps to worry about, but I do have six hens that are in obvious stages of 'unintentional' neglect. I can tell you what my bottle says of the Adams, and then I'll tell you what my game plan is.
The Adams Flea and Tick Mist came from
Walmart in their pet department. I think it was around $7. It's main ingredient is Pyrethrin, and the bottle states that it kills fleas, ticks, AND lice. I have chosen this product over Sevin dust just because I feel that it might be easier for me to spray something on my girls, rather than try and dust them. Either way, I'm sure they will put up a fight. There are all kind of warnings on the label, and honestly I am choosing not to even read them. Desperate times require desperate measure, and my sole concern has come down to bringing my flock back to health

And id the Adams doesn't do the trick, I will use the Sevin. Because of your chicks, though, you may need to take a bit more precaution. I will be spraying as much of this stuff on my girls as they will let me, by seperating their feathers to get as much down to the skin as possible. I will also be doing a THOROUGH cleaning of the henhouse, after which I will spray more of the Adams on whatever surfaces I can - such as the roosts, boxes, floor, whatever. While I'm doing this, I'll wear a dust mask. I will also be building them a dust box with DE added - this will help with maintenance after I treat them. I will also sprinkle around some DE in the henhouse when I put the new shavings in.
I have also ordered Wazine-17, because I'm sure my girls have worms, and I should have treated them months ago

Today, I will try and track down some Ivermectin Pour On, and I will use this product to follow up with after 14 days from the Wazine. From my understanding, the piperazine in Ivermectin will not only take care of the worms, but will also kill any lingering/newly hatched lice remaining on my flock.
This has been a HUGE wakeup call for me. I have one girl, Lily, who is in really poor condition and I can only hope that it's not too late. My personal insistance on keeping things 'natural', has turned out to be very detrimental to my girls. As far as the ACV that was mentioned in your post as a preventative for lice and mites, I can personally tell you that it does not work. I have been adding ACV to my waterers for months, yet here I sit with a lice infestation. ACV IS good in many other ways though.
I really hope that everything works out with your little chicks and the rest of your flock. I think it's very good that you are addressing the issue and not taking a back seat to it. I'll watch your post to see how everything goes. There is so much to learn!!! Good luck!