Well thats your choice, but you might want to read up on mites, and what it can do to babies as young as you have, and sows that have just given birth....basically it can result in death.
It is your choice to keep that many animals, so it is your responsibility and the animals right to get medical care. It is illegal for you to leave them there suffering.
Sorry if I sound harsh, but you sound like you are allergic to the vet!
There are lots of treatments that dont involve a needle, but if it has got to the stage where hair is missing here there and everywhere, that will probably be the fastest and most effective method.
Take them to the vets, even if not for treatment, just for an opinion