Bumblefoot-unable to remove core. What now?

have a large breed chicken (Rainbow Dixie) that developed bumblefoot on both feet. We watched videos that show to go in and cut the infection out. We soaked, I Epsom salts removed the black scab and then cut it open but were unable to find the infection core so nothing came out. We cleaned and bandaged her up but don’t know how to proceed. She is our favorite and we don’t want her to die. We don’t have an avian vet who will do it for us. Any suggestions? Will we have to go back in until we are successful at finding and remove the white core? Can this be treated with antibiotics or any other way?