There are a couple of ideas going on here that should probably be looked at as seperate issues.

-When a mono roll tacks like the do, it uses the roll of the boat from one extreme to the other to force wind and water accross the sails and appendages. That produces the forward thrust. We used to sail J22's w/o an outboard and the three of us would all get up on the deck (w/o sails) and "rock" the boat to the race course (save weight w/o the engine). The keel and rudder would provide enough thrust to move us along.

On cats you can't get the same extreme rocking motion to move the foils enough side to side b/c of our wider beams. However there is a trick in light air...

-Ooching is for and aft instead of side to side. I think it may be legal in a very strick and limited usage to help a boat surf/plane, but not anyothe time. Used like puming the sails to induce surfing.

-Water in hulls... bad at all times. If you have enough water to help pitch the boat forward on a wave, you're already going to be going so slow that it doesn't make a difference.