After discussing with my extracts friend, after doing a cost comparison of essential oils vs the iso, it was a pretty easy choice for me in this specific scenario. I'm not hating on them, not at all, in fact I'm a fan of using the essential oils in many areas. It's also a good deal easier to get mixed since it doesn't require an emulsifier.
That rotation is key, but, and this is a huge but if you live in an area that already has mites that are resistant to any one of them, it's super easy to achieve resistant mites. They're practically built for it. The only crop I've lost was to root aphids, didn't know what they were until it was far too late. Let me find some papers for you discussing miticide resistance. They are known to develop resistance to multiple miticides, which leads to further problems. If I could ask you, if you see them again, would you be willing to do a side by side since you're already making an application every 3 days? Do the isopropyl:water (1:1) on however many plants you're willing, and then your usual treatment.
I ask this because we've already been seeing mites in SoCal that are resistant to Forbid4F and
Floramite.
http://anrcatalog.ucanr.edu/pdf/8033.pdf
http://msue.anr.msu.edu/news/how_to_handle_resistant_spider_mites_in_your_greenhouse
http://aginfotoday.com/News/Miticid...ider-Mite--6-Management-Tips-2016-09-19/15247