No, but please give us a full report should you ever try it. :)

I do not know what Mighty Wash is but I will tell you this: I am a rose grower and spider mites can be a real problem on them. We use what we call a water wand...it is really a homemade wand that produces a hard shower of water to sprayed on the undersides of the leave. do this every other day for a few days and mites are gone. It knocks the mites off and disrupts the breeding cycle. No chemicals, soap, whatever needed. I've never had spider mites on hoyas but I'm sure it would work the same. Any hard jet of water will work you don't need a special tool.

I wish I could that but it's impossible with 106 potted plants in the house. :-)