I advise against pinching the nose and blowing or if you do take it VERY gently.
I did the valsalvar maneoeuvre coming off a cold years ago and perforated an eardrum on the ground and then had 2 months off flying.
On the odd occasion where my ears have not cleared I now let nature takes it's course and only resort to swallowing.
It's simple - if you're not fit do not fly!