I started using an oxalic acid vaporizer. It's very cost effective and very effective against mites. If you are handy you could make a vaporizer, I bought mine for about $130. OA is cheap and the treatments are pennies a hive. OAV is still not "legal" in the us, but well on it's way to being legal. It's legal in about 20 countries now and has been widely used in the US for the last 10 years.
Just thought I'd post what is working for me.
Robbin
Just thought I'd post what is working for me.
Robbin