As I noted in my trunk disease management page, there are few options to provide protections on these wounds. The bottom line is that you should pick a day without rain in the forecast and provide a protection (Topsin-M, Rally, even Dreft, or B-lock (new paint material), please see the trunk disease management page for more details).
B-lock is a latex paint with Boron, and the previous studies showed the efficacy against Esca and Eutypa dieback. If you cannot find B-lock in nearby co-op or chemical distributors, you can find them at Farm Supply Company, they are in CA, but they will ship to VA.
(B-lock applied trunk)Also, if you are interested in helping me on data collection, I have a small supply of B-lock that I would like to test out in a field experiment.