Bumblefoot is a bacterial infection (usually staph) that happens when the bacteria enters a break in the skin. It is not contagious in the usual sense, but it can be transmitted by touching the infection especially if you had any break in your skin, so best to wear gloves while treating it, to be safe. It's not something to panic over, just use common sense about it. I never isolate a bird for this unless needed to keep that bird safe. Often separation will just cause more stress for the bird.
I use vet wrap or co wrap (tractor supply has 4" rolls that you can cut to size) in the horse section. I cut them 18 -24" long and about an inch wide. It sticks to itself and they usually leave it alone. When you wrap the foot if you carry the strips up and around the ankle as well, it will stay on very well. You will need to use bandage scissors to remove it (they have one blunt tip so you won't accidentally stick or cut the bird). Make sure not to wrap too tight, just enough to keep it covered and protected.
This is the treatment I use for most cases: https://www.tillysnest.com/2015/12/non-surgical-bumblefoot-treatment.html/?spref=pi
It's important to get all the gunk out. Chicken pus is firm and white or cream colored, kind of cheesy. It can take some manipulation and squeezing to get it all out. Some lesions don't have a core and are more superficial and may not have a lot of gunk under them.
You can fill the hole with plain neosporin or plain triple antibiotic ointment. Cover with a bit of nonstick gauze or telfa pad and then wrap. Change the bandage, reapply ointment and re wrap daily until you know it's healing well, then you can do every 3rd day or so til it's completely healed.