Meanwhile ... can you soak his feet in a basin of warm water with some Epsom salts added for 15 to 20 minutes? That will help clean his feet and soften the scab. I'm not an expert on treatment. Perhaps @Eggcessive can advise or give some links that will help.
I agree with soaking his feet daily in warm soapy water, or with Epsom salts, or a disinfectant such as Betadine or chlorhexidene. There are a number of ways to treat bumblefoot, but prevention is best. Make sure to habpve lower roosts, soft dry bedding under the roosts, and prevent muddy conditions. In this earlier thread today, there are different ways of applying a dressing. https://www.backyardchickens.com/threads/bumblefoot-is-it-healing.1641884/
Yep! Bumblefoot, soak his feet in Epsom salt for 15-20 minutes. Make sure the water is not too hot but not too cold. Then clean with Vetericyn, apply prid, pit a little square of guaze over, and wrap. Be sure that you do not wrap to tight, then in around a week or two, you will see it start to "come up." Once it gets lose, clean it, and peal back the scab with sterile tweezers. Pack the wound with Neosporin, tripple antibiotic ointment, (NO PAIN KILLER! ITS TOXIC!)
Apply guaze over, and wrap again with vet wrap. Try to do this process once a day. When you remove the scab, you might want to put chicken booties on to cushion, and protect. Hope this helps!
Sometimes the scab will loosen and peel after the first soak. The staph infection inside may be yelowish creamy or may be in a hard plug “kernel” but both need to come out.
Spray vetrycin or similar and pack with Neosporin “with no painkiller and wrap with vet wrap. check every couple days. Should heal well within about a week to 10 days.