I've said this before but I firmly believe that when power righting a catamaran from turtle, tie the line to the top (submerged) side of the mast post and tow the boat backwards very slowly and into the wind if possible. It will pop up like a porpoise. Trying to pull it over from the side leaves more potential for damage and for the boat to spin at awkward angles.
Top of the mast post? You mean at the mast base? or at the mast head?
What do you mean "tow the boat backwards"? In the direction of the rudders? Can you draw us a picture?
I'm not getting what you are describing.
Its an interesting topic and something we should all have worked out before we spend two hours (or longer) in the water.
What about untie-ing the spin halyard and using that to pull the mast up from a turtle?
