The Blue Kote probably stings.
Is he still bleeding? It will usually stop and clot on it's own. Sometimes I don't do anything to a broken spur, other times I may wrap.
In your case, it looks like it may be torn and quite a bit of quick is exposed so he will be very tender for several days. Wrapping may be a good idea, but it's going to be sensitive and he will indicate that it's painful while you're wrapping.
To wrap, spritz the spur with Chlorhexidine or Povidone Iodine. Let that stay on a few minutes. Apply triple antibiotic ointment to a non stick gauze pad and cover the spur. Wrap from foot to above spur with vet wrap, keep that non stick pad with ointment over the spur.
Check daily and change daily. If the pad sticks to the spur for some reason, don't just pull it off, use your Chlorhexidine, Povidone Iodine or Saline to wet the gauze and gently work it loose.
The above wrapping instructions and steps are what I have done with my own roosters multiple times over the years, it's important to check wrappings make sure they are not too tight on the feet and legs and change them. If the wrapping gets wet, change it more often.
You can choose to just let him be - I've done that too and just monitored the healing process very closely.
