Well...according to my personal experience...and some source from Internet...it is more related to where you generate the "air" stream... if you use the right place..say..your diaphragm to breath in and out the air stream instead of the inside of your mouth... the air should be less warmer and therefore generate less moisture.. that is why the water inside the sax is lesser... try some exercise to see the difference..although there will be still some water inside the sax...