Yearling heifer vet dehorned 3 wekks ago. Kept in because of flies the let out as all looked good and dry but hole had not started to fill in. She was done at the time, and redone, with a pour-on systemic wormer and sprayed with blu spray. Today after a rain there is greyish goop coming out of the hole. Does not smell. Can I flush it out with something and is that a good idea. Thanks