I gave in a year or so ago and just let the damned stuff grow. And grow. And grow. Until it threatened to break out of the house one night and lurch down the hill moaning "brains....brains...." but I let it stay on until the end of winter.
It is making a steady counter-assault after I decimated it with a surprise dawn raid a few months back.
Strangely enough if you do grow a big honking faceful and then shear it all off you find yourself thinking you've forgotten something or left something at home

and suddenly you have a lot of free time because thoughtfully scratching it was taking up two hours a day.