Just because someone puts it in a book, does not mean its a valid exercise. I do not understand how anyone thinks that kerosene or anything else liquid is going to penetrate the cells of a hickory tree, in life, or death. The cell walls are made to prevent that kind of foreign penetration. Now, if you use white oak, that has columns of cells and you not only can pass fluids through the cells, but also blow air through the strands. You can't do that with red oak, however. So, go ahead and soak the wood all you want. Its not a sponge. Its will stink for a long time, simply because their are pores in the wood, but not in the cells where the kerosene will go. If that hickory stick could absorb kerosene, then when you take it out of the soaking tube, kerosene should run out of the stick for at least 15 minutes. No?
Oh, I happen to like a lot of the things that Dr. Sam Fadala has written, and I bought his book, too. But, I also paid attention in Biology class in HS, and again in the Botany portion of my biology class in college. Even as smart as people like Sam are, they too can fall victim to passing on junk that simply does not work, simply because they were told that it does work, and they never sat down and actually studied the matter. It happens to the best of us. I have never read an article where Dr. Sam actually soaked a ramrod himself.
Checking ramrods for run out of grain is the easiest thing to do, and the best way to insure that the stick won't break down during use. I get queer looks from some vendors when they see me checking the hickory sticks they sell first for straightness, and then for grain run-out. Some realize I know what I am doing. Some haven't a clue what I am doing and would not know how to pick out a good piece of hickory for their own ramrods. The sticks they sell come in 48" lengths. Since they don't know how long a barrel you are working with, there is not reason not to try to sell rods that have run out at one end. For shooters who are shooting shorter barrels, they can cut off the bad end of the stick and have a servicable stick for the rest of their lives.