I feel like on the principle of harm reduction we should just let these people try it, in the correct, safe, form/dose with medical supervision.
As an aside, ivermectin is a GlyR agonist, so it seems at least scientifically plausible it could do something for some people with autism. But I'm not a doctor, just an autist with a special interest in psychopharmacology.
I don’t think the principle of harm reduction can justify this kind of active child abuse.
While veterinary formulations are not meant for human consumption they are meant for internal consumption [1] by the intended species and dosage is actually easy and accurate, at least when the standard anti-helminthic dosage of 200 µg/kg is used since in that case the dosage can simply be set on the syringe just like it would be done with a horse. The difference between the human and veterinary formulations of Ivermectin is in the used base, a paste for the veterinary version versus a solid filler-diluent for the human preparation. The active ingredient is identical and sourced from the same Indian manufacturers like is the case for so many other off-patent medications.
[1] there is some off-label external use of Ivermectin paste for dermal conditions, the efficacy of which has not been proven
At worst, you'll quench your thirst, but at best, you may get rid of that pesky tumor!
The only proactive solution is deterrence, which starts with dealing with the idiots doing it in public.