Boy I hate spider mites, but they did introduce me to washing my harvest. Have you inspected the underside of your leaves? Their poop is easier to see than the bug.
I moved where my outdoor plot was (away from tall grass), and started using companion plantings. No more run-ins with those jerks.
But now I wash all my outdoor. No matter what. Harvest by the branch, de-leaf everything I can easily snip, wash and hang. The sheer amount of junk that comes off is staggering, and quite frankly gross. It is a pain in the ass, but well worth the effort. Added bonus is an even, slow dry no matter the nug size.