"Eschew flamebait. Avoid generic tangents."
That something sounds strange doesn't particularly lead me to question the likelihood of efficacy.
The evidence on something's efficacy leads me to question something's efficacy.
You mean something that's demonstrated to have a statistically significant protective effect in a majority of studies but was attacked mercilessly by the pharma industry and the media they fund because they can't profit from a generic drug like that? https://c19ivm.org/meta.html
Does horse dewormer do anything significant for large populations in first world countries?
No. (Save for regions with a intestinal parasite problem)
Elsewhere it gets rid of a significant number of parasites, making people healthier, and improving their chances WRT everything else, the common cold, influenza, COVID, etc.
If you have worms, take a dewormer course.
If you don't .. it won't do diddly squat for COVID.
Statistics!! (Sometimes there's correlation but that ain't always causal).
Then you have Remdisiv, which definitely killed 10's of thousands of people, if not more. That's the real story of COVID, at least in the US. The countless people that were experimented on with one of the most dangerous drugs to be invented in recent times.