1 part water, 1 part isopropyl rubbing alcohol (i'm using 91%) and a few drops of dawn liquid dish detergent.
mites die within seconds, and it's just as effective for eggs.
my two-spotted mite population disappeared over night because of this solution.
http://www.getridofthings.com/get-rid-of-spider-mites.htm
that's where i got the info.
cheers =]