Yup, that’s bumblefoot. Good article on it and treatment options here.
It can take a while to heal because it heals from the inside out. It’ll require multiple soaks and daily wrap changes. Through the soaks and the Neo, the scab will naturally loosen and then you can try to remove it and the attached core. The core is the hardened infection.
Some people use antibiotics – like Baytril or Clavamox – and an anti-inflammatory – like Metacam. But soaking and wrapping should take care of it so just be patient. It’s a gnarly infection.