I use both as well, I am a die hard charcoal cooker but find the time and expense don't always justify the use of it exclusively. I have a high end Summit with the dedicated smoke box burner. Gives me the best of both worlds on fast cooking food.
Yes, I do pre-soak. I use 3% and dilute it, about a table spoon in 16oz of water. I soak for a minute or two then rinse.
If you search the forum you will find posts regarding this, lots of expert growers here. I used some of the tips at this link with great results...