If you are trying to prevent termites from getting into the wood you can certainly treat the soil beneath them with the Dominion 2L. Dominion would not be a product to treat the wood with as it would not last more than a few months. You would want to treat the wood with Boracare which will actually soak into the wood rather than just sit on top of the surface and will protect the wood as a whole. Once dried you would want to seal the timbers to make sure the Boracare stays in the wood over time. If sealed, the
Boracare will last for the life of the wood protecting it, and once the wood has dried, it is safe to use as you intend.