Spread on the Tru-Oil with a foam brush. Nobody mentioned to brush with the grain (more on this later). After a few minutes, the excess was wiped off with a rag. A now very flammable rag (the Tru-Oil cures via oxidation, an exothermic reaction— if you leave a few soaked rags balled up in a small, enclosed space, your house will burn down). I hung my rag on the outside railing with the pair of ceramic magnets that came out of my Greco.
This coat is for sealing the wood. Whatever that is.
24 hours later:
Filling time! I wet-sanded with 400 grit paper with Tru-Oil as the lubricant. Working in 4″ x 4″ sections, the goal is to create a slurry of sawdust and oil, and rub that into the grain. “Rub”? The instructions say “burnish”. I rubbed ineffectively with my gloved fingers.
As it happens, merely rubbing it in makes a mess. I filled the grain, but the guitar looked awful. An uneven, splotchy finish covered the body. I also learned that you shouldn’t sand with the piece resting on painter’s pyramids.
After the mess dried, I sanded it back with 320 grit dry paper, not quite to bare wood, but removed the blemishing. Then I steamed out the new dents.
Placing the guitar on a clean linen cloth, I then wet-sanded with 400 (and Tru-Oil). This time, I burnished with a linen cloth. Worked really well, and the guitar is much less ugly.
The guitar is very smooth to the touch.
There are some horizontal lines on the pictures of the front and back, and they were probably caused by brushing on the Tru-Oil cross-grain. Whoops. Hopefully they will become less visible with more coats and burnishing with the grain.