Epoxy encapsulation works, but it should be used only if the encapsulation is done while building the boat. It is almost impossible to encapsulate a ready structure reliably and that will result to a situation where there is water trapped inside the wood and it can't evaporate. And that means that the wet wood freezes at the wintertime and it is destroyed in a few years. Wood movement, UV light, scratchs and knocks may break the epoxy surface. You have to keep the surface in perfect condition to keep the water out.
Ethylene glycol is an effective rot preservative.
But it's hydrophilic, which means that it attracts water. So it acts just opposite what you would want it to work. It kills rot, but so does a huge amount of other substances who don't draw water to your boat. Even after coating the surface with paint or epoxy it will keep attracting water and the water content in the wood will be greater than in untreated wood. So, it does nothing to impregnate the wood, it just kills rot and after that acts just the way it shouldn't.