When I have this problem I break out the Dremel. You can find bits at the hardware store that look like bits you'd find in the dentist office. The two I use most often are one that is triangle shaped and one that is round shaped (I should add that these are the carbide bits not the stone/ceramic bits). Use the dremel, just like the dentist, and carefully drill out the cavity of epoxy. Then take scraps of the same cloth you used for the wrap, apply the epoxy and stuff them in to the cavity. Make sure you have enough cloth that it protrudes from the cavity. Wrap with plastic wrap, and then wrap masking tape tightly over the top of the plastic wrap. If you want you can also apply pressure with a clamp as well. Let fully cure, remove the tape and plastic, and sand. Has worked great for me on about a half dozen knife handles. Just don't try to get over agressive and do too many voids at one time.
