It seems that some people have yet to read "Stick and Rudder" by Wolfgang Langewiesche. He states time and again that it is the stick position that is crucial in stalling (or rather in NOT stalling). I was taught the sideslip in my RAAus training as it is indeed part of the syllabus. This was in a low wing plane. Although you have crossed controls the stick should be forward, or neutral. As I now fly a plane with no flaps it is part of the toolbox for me, especially when practicing forced landings. It is better to have a bit too much height when approaching the paddock you have selected, and then slipping off the extra height when certain to get in rather than the other way round, ie find yourself too low and unable to make it.
As stated by some of the others on this thread, if you were not taught this as part of your initial training then I would suggest getting some training on this very useful manoeuvre with an instructor at a safe height.
My 2c.
Rgds
Neil