Milking is what I have read other members describe as "pumping" the tube with your hand between a 1/2 inch to an inch - I guess it is to increase or at least ensure blood flow. I have never done a test to see if starting out flacid an not doing kegels is any different with kegels - also starting...
I've also made a couple tubes and use an automotive style pump. My biggest questions/concerns still are:
do kegels make a difference?
does using water make a difference?
does milking make a difference?
should your peehole be sealed?