Classic sites for abcesses are top of the head, under the chin, side of the face & sometimes base of the tail, if the vet had lanced the abcess you would have probably had to go in the following day & re open it anyway, so if thats the case a sterilised scalpel would have been needed .
Rather than pick away at it with your fingers, thats the best option & it was what i was told to do by my vet last time i took a ferret with an abcess, once the puss was removed by flushing with a saline solution
Naturally theres a need to see a vet on occasions & people arnt being told t