The most popular product that we have for treating drywood termites in furniture or other areas that are not easy to reach is Premise Foam. You have to drill a hole into the damaged piece of wood and treat it directly. The Premise Foam is considered better for termites because the foam will expand which gets you better coverage area inside the wood. Also, Premise foam is a non-repellent product meaning the termites can pass it around to other termites in other parts of the wood or furniture. If you know exactly where the "kick out" hole is where the termites are pushing the pellets out of, then you should drill directly into this hole and foam directly at that area.
Here is a link to the Premise Foam for you to read about further: http://www.domyownpestcontrol.com/premise-foam-termiticide-18-oz-p-317.html