Some guff:
http://buildingpreservation.com/inde...tion&Itemid=85
Whatever fluid you use you need to apply plenty of it if you want to kill them when either chomping their way in or chomping their way out, it's all about retention of the active ingredient(s) I spent years sawmilling and having timber treated, it was CCA pressure treatment back in the day, retention of the correct minimum amount of salts was very important for successful treatment.
Also, so far as I'm aware water or solvent based won't penetrate lacquer/varnish very much....
Lawrence.