I have tried a couple of different products, the best to me is the following:
Insecticide | %post_title%
to that recipe I add about 1/4 cup ispropyl/rubbing alcohol and about 1 tsp of cinnamon powder. Adjust the quantities to what works for you...a good tip is that you must smell the Bronners when you spray the concoction.
It works like a charm and is safe to use indoors too.
With spider mites its best to have a preventive programme, so spraying at least monthly is advisable - and that is ALL plant surfaces except roots. I have learnt the hard way to isolate and thoroughly spray all new plants too.
Any other remedies ? Maybe we can keep in one place as a sticky ?