I've never tried a hair tonic. Honestly I don't really even know what it is/does. But I know it's that green stuff on the counter at my barbershop!
I use a hair tonic like I would use any other hair styling product. I put it on before I comb my hair, and it more or less helps it stay in place.
The Lucky Tiger tonic has oil in it, and help my hair keep it's shape a bit better. It's not so much oil that my hair feels greasy, though. The problem is that in the summer, it causes bumps on my skin (I think it clogs my pores) since I sweat so much. I live in the city and walk everywhere, YMMV. The CP is not quite as good, but it does not cause bumps, so I use that when it is hot.
My guess is that living in Texas, you might want to try an oil-free tonic.