I think consensus here at the forums is that the best way to clean your guitar is with a cotton cloth and a tiny amount of water. I've seen Lemon Pledge recommended at a couple of guitar manufacturer websites, but I would be afraid of buildup after a while. On my gloss guitars (an old Ibanez and my current Epi EJ) I use a touch of dishwashing liquid in the water occasionally. On the Nitro (Gibson) just water, but only very very little - like the mist from your breath.