People has different methods with varying degrees of success. Some soak the legs and feet with olive oil (any oil would do). This basically suffocates them and does nothing for the thousands that might be lingering nearby. Some mix sulfur powder with Vaseline and apply it several times a day for a minimum of 2 weeks (who has time for all that). Then there are those that use the 'trial by fire' method, or more accurately, the gasoline and baby butt cream method. This fun filled method requires that you DIP your chicken's legs and feet in some gasoline (yep, like the kind you use in your car), let them air dry and then massage in some A & D ointment on them. That would be Day 1. Day 2 you just rub in some more ointment and then Day 3 you do day 1 all over again...that's the end of the treatment. Word of caution. DIP !!! the leg in the gasoline. DO NOT RUB IT ON OR RUB IT IN...JUST DIP AND LET THEM AIR DRY !!! And don't repeat this treatment again for a few months at least. The one good thing about it is that the gas gets up under the scales and kills not only the adult mites, but the nits (or eggs) as well. Other options don't and could take up to several weeks of daily (or more) applications to completely kill them and the nits off. Ivermectin can be used also, but depending on where you're located, could require a Vets. Rx.
Hope this helps and good luck !!!
-kim-