I don't know if it is bumblefoot, but it could be (Diseases & Injuries)
It sure looks swollen (and painful). I do know that infections in birds don't appear the same as what we see in humans. They may begin as a pus filled sore, but as the infection brews, it will harden into a firm core. Sounds like that's what you removed from your bird's foot. If the infection has spread throughout the foot, you will probably need to treat it with more than an ointment that cannot penetrate deep enough to completely eradicate the bacteria. I was once told to try LS-100 (Lincomycin-Spectinomycin administered in water) for a serious foot infection when I had a guinea that walked with a limp and had a swollen foot. I don't know if that medication is still available over the counter at feed supply stores, but it worked to reduce the swelling in my guinea. However, that was almost 10 years ago, and I know that some antibiotics have been taken off the shelf lately.
I'm sorry I cannot offer any advice as to whether you should try to remove a bacterial plug from the top of the foot (if it is there). I really don't know if it would help. I hope you can get a more educated opinion about the best way to treat this problem.