If it's bad enough that something may be under the scab, as a human surgeon, (and a person who worked for vets for 8 years", you have to open it up and remove all necrotic tissue. That's the only way the body can then fight the infection. We see internal medicine doctors try to use only antibiotics and the infection will get worse. Yet 24 hours after I drain them and debride all dead tissue to healthy tissue, and give the correct antibiotics, the person is remarkably better. Whether it's people or animals, the principle is the same. The body can't fight an infection with a pus pocket or dead tissue. If you want to flush an infected spot, I highly recommend Hibiclens. It's what we use to scrub before surgeries. I've healed huge diabetic ulcers with it by soaking 2x/day for 10 minutes. If you can't soak, gently rub it on the area for 5 minutes. It kills all bacteria, fungus and yeast for a full 24 hours after a 10 minute application, but don't wash it with anything else in between. You can apply an antibacterial cream or ointment.