The shaft of his $15 cue was from a bowling alley.
I tried it once and was amazed it actually shot good.
Albeit the cue was some 21+ oz and some 60" long.
At that time when it was made, it was probably the best source of maple they had down there in the Philippines. Since those US bases were built there right after WW II, maybe they had good maple on those alleys. I was shocked to learn later, they cut those planks on an angle to get more shaft material. Even if they crosscut the grain. A ton of them became crooked after that I bet.
That wasn't Efren's first cue. He won it on a bet. He had someone used it then the tip broke in and he liked it. It became his main cue after that. He won the US Open and World 9 with that cue.
Bowling alley shafts here is just a gimmick. Sorry, those boards were not cut with cylindrical end-product in mind. The best shafts are from boards cut with pool shafts in mind.
Here's a shaft supplier who is probably the most popular source today.
http://champeau.com/en/product_billiard.php
Double-taper primary sawing. This technology allows for alignment with the natural grain of the wood. Only straight-grained white boards are selected for these components.