Wafers are flat pieces of metal that hang inside a lock similar to
the way pins work.
The wafers stick through the plug preventing it from turning,
much the same as pins in a pin tumbler prevent that from turning too.
They have holes in the middle of them for the key to go THROUGH.
The cuts on the key push the wafers up or down, corresponding
to the cuts in the key.
This in turn stops the wafers from preventing the plug to turn,
because there is no wafer part sticking through it if the right key is in the lock.
There is advice on the forum the opposite of what I will offer now,
which is to:
* Use a ball or snowman to tickle the wafers
* Use very light tension.
This works for me all of the time.
http://colt.projectgamma.com/lock/fig-06.gif
Do a search for WAFERS