I can understand your wish for natural remedies until it comes to parasites. If you do have them, you need to use real pesticides or your birds will suffer. But follow the directions.
A couple of questions:
How old are the birds?
Number of birds?
Area of the coop and run?
Have you checked for parasites?
Pictures of set up can really help.
Look up pin less peepers. They often work well in small set ups.