Did you remove the plug from the bottom of the toe? That's the yellow spot in picture #4. After soaking, when it's softest, you need to remove that and then squeeze out any pus from in there. Chicken pus is very firm, like a cheesy consistency, it may take some squeezing and manipulating to get it all out. It all has to come out before healing can happen. You can also apply decolorized iodine to that spot and wrap it overnight and that will soften it up also. Decolorized iodine (not the same as betadine) is in most pharmacies in the 1st aid section. Once you've cleaned it out well, fill the hole with plain neosporin or plain triple antibiotic ointment and wrap it to keep it clean and dry. Change the wrap and reapply ointment daily until you are sure it's healing up well. You may have to clean it out more than once, depending on how much stuff is in there. For very stubborn bumblefoot I use sugardine, this thread has info on that:
See post #8 here
https://www.backyardchickens.com/threads/bumblefoot-not-healing.1443809/#post-23973555