It doesn't work. If it did rodents are clever and figure out what is killing them.
Three methods of dealing with rodents according to Howard E..
Sanitation
Exclusion
Elimination
First method, bulk feed in metal barrels. An actual treadle feeder and pay close attention to the negative reviews, most are junk. Remove all other human sources of food like compost bins or trash. Clean up the paths the rodents use to travel from their burrows to the source of food. Usually between 20 and 100 feet away, any longer and predators get them quickly.
Second method, used ONLY after you used the first method. Build a Fort Knox coop and run. No holes or gaps larger than a quarter for rats, a nickle for mice. Use metal, wood can be chewed through, even concrete, rodents HAVE to chew to wear down their teeth or the teeth grow into their skull.
Third method, and for a reason, it is unending. Poison and/or traps. Cheap to do, the rodents learn very fast to avoid, a never ending expense with declining efficiency from day one.
However, if used in conjunction with the first method the rodents are forced to take the bait or fall for the traps. But, entirely unneeded unless you are dealing with hundreds of rodents that overwhelm the treadle feeder. Even then, a properly designed treadle feeder has a narrow and distant treadle that is unlikely to be overwhelmed, a spring loaded door so a half dozen mice can't just push the door open or up, and it should have a door that swings inward, not up, so it can trap the few rodents (or dozens if you are dealing with a swarm) that do get past due to swarms or rodents.
On the few occasions I have heard of this happening the rodents smothered themselves by the dozen. One or two rodents will be fine so be ready to lift the feeder off its bracket and dump it in a metal barrel so you can deal with the rodents. Commercial flocks have reported that it happens once per feeder and that the rodents refuse to swarm that feeder afterward. Even if they cloroxed the feeder the rats know or remember. In a few days to a week the rodents are gone.
You are doing well with your research but discount the magic fixes. None work. Sanitation, exclusion, and elimination do work, with various efficiencies and costs in order of their listing. Cheapest and most effective listed first.
