Hello Pammie,
From what I have read in this forum (though I do not recall hearing about raw garlic and cod-liver oil) the best way to treat worms is with Flubenvet. People have tried all kinds of alternatives but Flubenvet keeps coming up as the best. If you type
Flubenvet into the search box in the top right-hand corner you will find all sorts of information.
As far as redmite is concerned this has been a growing issue and there has been loads of discussion about how to keep the little ****ers away. The best way so far seems to be using poulty shield to disinfect the inside of your house first then using a diatom slurry. This is diatomaceous earth, a powder, which you mix into a paste with a dilute disinfectant such as poultry shield and a little washing up liquid. You paint this on all the surfaces of your perch including the ends. You also paint some into all the cracks and crevices of the house and where the perch sits. Again if you type
Diatom slurry into the search box you will find more information.
I read today that one forum member used a steam cleaner to clean their coop successfully. I am going to watch out for the comments on this because it seems like an effective way to clean the coop. This person put a handful of DE dust in the coop and closed all bar one of the access points. A short blast was then given with a leaf blower to spread the dust around the house.
Good luck with your hens, Pammie, and keep us posted