The various options for control for varroa work for a while and then no longer, as the mites develop resistance. And in using them you prevent your bees developing their own natural resistance. You keep weak bees alive and allow them to send their defective genetic material into the local environment, undermining any resistance there.
It is far better to adopt the preventative approach used by all other kinds of stockholder - by bringing in or delevoping resistant bees, and keeping them resistant by multiplying from the best and eliminating the weakest.
Genetic hygiene is a permant solution to varroa, and other pests and diseases. It is the way nature keeps species strong - the only truly 'natural' way.
The treatments bring benefits only to treatment manufacturers, their supply chanis and advertisers. They invest a great deal of money selling their products by telling you that treating is the 'proper' way to fix the problem, and making up stories about how the great 'cure' is just around the next corner.
These are not beekeepers, but the worst parasite of all. They don't care about healthy bees, they care about their profits, period.
Fight back on behalf of bees and beekeepers by learning the simple techniques of clean beekeeping. And spead the word - these people have budgets of millions of dollars - but we have the internet...
PS See the selected links on my website for more details.