Battery powered leaf blower works well. Compressed air is ok too if the pressure is not too high. This way you don't scratch your intake vanes with a vac attachment. Blowing air in the front seems to get everything out.
This thread reminded me that I haven't cleaned out the front in a while, so I used my Master Blaster car dryer and it worked great, blew out about a 1000 leaf pieces from the two sides.