Rose,
When using the new device (I "invented" it so please email me privately
with any questions), it is important to pull the nipple out and hold for
60 seconds before releasing the pressure.  I usually do this 3 times
just prior to latch on and ask the mother to use it between feedings as
well.  You can use either the flanged cone end or, for more concentrated
suction right at the base of the nipple, turn it around and use the
sleeve end.  I hope these instructions help you to be able to use it
successfully!
Edie Armstrong