Just for kicks, home brewery stores sell chipped oak for addition to beer...
Oak's Balancing Act | MoreBeer
Has this been applied to vaping?
There was discussion and if I recall it was tried with very good results using a dark glass bottle and chips. Still the chips soaked up a lot of juice. Another interesting thing besides adding that rich oak wood flavor to the mix was it shortened steep time drastically. If I recall correctly what usually too 3 weeks was ready in a week and the color of the vape was far darker, thicker and richer in flavor then the baseline sample that was steeped naturally with no wood added. I in fact still have both samples and the difference is still dramatic even after a few months.
Here's some good reading on this and towards the end of the thread I give an in depth review of the results.
http://www.e-cigarette-forum.com/fo...e-need-help-1st-try.html?highlight=oak+barrel
http://www.e-cigarette-forum.com/fo...-oak-barrel-reserve.html?highlight=oak+barrel