You have three options to treat wood boring insects in furniture. You can have them professionally fumigated--placed in a fumigation chamber with a toxic gas that can penetrate the wood. It can be difficult to find professional fumigators unless you live in the south or the west coast where drywood termites are common, but call around to local pest control companies, and ask if they do spot fumigation of furniture. You can freeze them for 10-14 days if you have access to a large commercial freezer capable of subzero freezing. Be sure to seal the items in plastic if you do this, otherwise water will condense directly on your furniture when you remove from freezer. Last, you can heat treat. Putting items in clear plastic and setting them in the sun on a hot day should be able to raise the wood temperature to 120 degrees or so for more than an hour. This temperature is lethal for most insects. Forget fogging or spraying insecticides. This is not effective and will not penetrate into the wood where the insects live.