As with any oil, I think it will give a slight yellow look, but it really does a nice job in popping the grain. I didn't think the yellowing was as prominant as other oil finishes, though.
I would definitely glue up your work before adding the oil, though. Oil will make the glueup difficult at best. After you're glue has dried, just take a foam brush and just soak the heck out of it. After about a few minutes, go back with a clean rag and rub it down, removing the oil. Then let it dry for a few days, then spray.
I use it for smaller pieces, mostly. I have a small tupperware (the kind that holds sandwiches) that holds my oil. I just dunk the piece in, turn it a few times, then wipe off the excess with a paper towel. Then I put it on some cardboard. The cardboard acts like a sponge and draws the excess oil away from the piece which seems to make it dry faster. I let it set for a day or two, then spray it with acrylic spray.
I think the big draw with lemon oil (other than Steve making it popular ), is that it has a nice smell. When your significant other comes home, they'll think you dusted the house (which is always a bonus, especially when you're hinting for a new tool ). You also don't have to worry about safety issues like noxious fumes, flammable materials, and oily rags bursting into flames. Its not a very durable finish, so that's why you cover it with a poly or acrylic spray.