Cures for scaly leg mites - Ivermectin drops?

[Montanacik]

My chickens have recurring scaly leg mites. I usually use a combination of kerosene and linseed oil to dip their legs in, which is very messy.
I’ve also tried A+D ointment.
Someone said they use Ivermectin drops on the back of their necks.

Can anyone verify this?
Where to find Ivermectin drops?

I would appreciate the help.

Chickwee in Montana