I don't think you're supposed to let an abscess pop on it's own. If it starts draining or pops on the inside your husband could die. And I agree with the poster that said antibiotics will not help an abscess.
When I had mine it was on my stomach (it eventually turned into a fistula because it wasn't drained soon enough). Anyways, I waited too long to call my doctor, so when I got his on-call nurse she told me to come on in to the ER. I went, they did xrays of it to see how big it was. I was told they were going to make a small cut and place a tube to drain it and that it was easy peasy.... well I was waiting in the hall to get taken back into my room and it popped. I yelled for a nurse and it was like a scene from "Trauma life in the ER" I was rushed to my room, basically cut open while I was wide awake, and they cleaned it out....that HURTS. Then I had to be admitted for 4 days to make sure I didn't have an infection, plus then I needed an wound VAC (not fun) because the wound was so big, they didn't close it up incase of another infection happening. It took about 4 months for it to actually heal.
I think you should go with your gut feeling and get a surgeon to take care of it.