2008 215sc speedster using in winter below freezing

[hmsiii]

I am winterized now but would like to use the boat in February. I did not use manufacturers directions, I pushed antifreeze thru the washout port which puts anti freeze in the supercharger and the intercooler. I could do this every time I take it out, but is a real hassle to do and a waste of antifreeze. In the 2009 owners manual it says blow 100psi air thru washout port to get water out of the supercharger and intercooler to winterize. Has anyone ever done this to use boat in freezing temps. thanks harry