Mr. J. T Brown who lives in Hornchurch in the United Kingdom claims that Varroa can be treated using a tincture made with green almond husks (not the shells) and alcohol.
After a month the tincture will be ready for use when it has been strained into a clean jar. A piece of linen should be fixed the full length of one dummy board (used when a frame hive is not full of frames). The linen should be painted with the tincture until it is saturated and placed behind the frames with the cloth facing the brood combs. After a month the dummy board should be removed, repainted and replaced.
Mr Brown has used this remedy for several years and his hives appear virtually Varroa-free.
"I leave the treated boards in the hives all year because the treatment is non-toxic and cannot affect the honey or the bees" says Mr (Varroa-free) Brown.
[Bees for development Journal #51]