I've a rocket blower, it gets some of the stuff out. when you use it, invert the camera above the blower, using the MIRROR LOCKUP function (read the manual). If you use the time exposure function the sensor is still charged and attracts the crap you're blowing around.
I also use an Arctic Butterfly, which helps with the more stubborn stuff.
For anything that's still stuck there, it's wet swabs (the specialist camera cleaning stuff).