There are two common ways to get the rod apart. Behind the knees works if you are alone. If you can find a friend use the four handed method, Stand facing each other, each person hold the front and back pieces. So you have two hands on the top, and two on the bottom. Then you both pull together.
As to prevention yes, sanding is bad.
Clean the male side with some alcohol (not Scotch, rubbing) and a rag, also use a Q-tip to clean the female side also with alcohol.
Ferrule wax is nothing but over priced unscented candle wax, just apply a very small amount to the male side. Rub the male side with a candle, then wipe away any excess with a rag (or you shirt sleeve). To much wax allows dirt to get in there. Another trick is to use "nose oil", this is the oil from along the outside your nose. This should not be done on metal ferrules as they oil is somewhat acidic and bad for the metal. It is actually pretty good for internal and slip over ferrules, and you don't need more crap in your vest.