They work. There are numerous Mennonite folk who work there at the store, and some former Amish too. I asked a couple people there about it and while I know religion is no proof against liars, I honestly dont think there were any lies involved in their responses. No one claimed 100% hatch rates, but supposedly if it is watched almost constantly, it can be as good as modern means. There is no actual air exchanged into the box, if you look, the hood is not actually vented INTO it, there are copper pipes that run through the hood, the lady and gentleman I spoke to wasnt sure what or if anything was IN the pipe, but it isnt venting air right into it.
They dont actually carry them in the store, theyre ordered from the makers directly
but theyve had one in a few times for various reasons, and they seem to think theyre quite well made. Im not vouching for them exactly, just that I asked something of the same questions.
Id guess the biggest reason they were ever effective, is they were first used in houses that had many people willing and able to monitor them 99.9% of the time. Either a grandparent who didnt get around much, several younger children who get made responsible, or a wife/mother/sister/aunt who is in the house a lot. Normally Amish families have 3 or 4 generations in or near to share all the work, and a granny may take much satisfaction in keeping an eye on such things. Now in a modern house, with so many distractions and all, I think itd be more than a little iffy
not to mention the fire hazard involved.
