Something that is a really great option for non-surgical bumble removal is salicylic wart pads. You stick the appropriate sized pad over the bumble, cut the cover plaster to size and stick on, then wrap as usual. You can do the epsom soaks as well with this method. The salicylic acid softens the skin until whatever nasty business is under there will lift out. Then you can use Vetericyn/sugardine and gauze to protect the wound and it should heal. Takes time but bumble always takes time. I’ve had a lot of success with this method (along with drawing salve like magnoplasm for more complex bumblefoot) and learned it here on BYC.