I'd flush and not treat with eyewash. There's an issue with it that I forget what it is but I think there was a CSI episode about it so it CAN'T be good, hahaha!
High ppm, symptoms of Mg deficiency (striping on that leaf) means lockout to me.. The flushing should do ya, and if you want to foliar feed, 1/4 tsp per gallon epsom salts will do ya much better, but try not to get it on the buds!!!! = burning throat sensation when smoked.

Honestly, this late in flower, I'd just flush, feed with a weak compete fert, and call it good. You're almost done anyway.