How about if the engine does not start by normal means then stop trying, fix the issue and resume in a normal high idle start setting. Would this not be much safer? How does one know his restraint would hold up to 60lbs of thrust. How about the part of the airplane that the restraint is connected to? What about the possibility of the engine mis-firing at full throttle and shearing all 6 prop bolts and spitting a 28" prop in your face? Remember most accidents happen when people start working outside the norm.

I think Ace has a great suggestion, pull the intake apart, true up the reed block. Assemble with no air leaks and try again but in a normal starting mode.