I started using met-blue back in the 80s on crocodilians, captive crocodilians often develop skin abscess from dirty water, later iv use met-blue on varanids for treating blister dieses. I don’t know why it works but it dose the job.
I can only offer experience based on other herps sins uromastyx are new to me! however I think it’s pertinent.
Needles to say this is just an opinion and everybody has one, but we all have different experiences, I for one don’t follow rules and prefer to pave my own road thru trials and errors.
In treating blister disease I encounter 2 major problems, the first being petroleum base ointments ( most antibacterial ointments are!) my second problem was dehydration.
This bacterial disease needs a humid environment to survive and multiply, Ointments encapsulate and allows the bacteria to flourish under skin, this is how we go from a little bubble to large scabs. The best solution is to drain the abbesses and allow it to dry, once drained met blue stops the progression and keeps the area free of bacterial growth for some time.
I use to keep such animals in dry cages thinking it will help the healing process, wrong!
In reality it prevents healing, first dry skin cracks allowing fluids out giving new breeding grounds for bacteria, the cycle starts over and over, new skin formation need to keep well hydrated, next especially for arid land reptiles witch are often affected by both aestivation and hibernation in nature, these animals are genetically programmed to shut down and stop feeding in these conditions, this slowly leading to dehydration furthermore halting healing, septicaemia resulting in weakened host.
It took years before I could successfully treat African varanids from blister disease, simply because it was on the belly and they are always dragging the belly somewhere, I lost many over and again thru the years. I have to mention these are animals from dealers and not only from my collection, part of my hobby is to acclimate imports.
The solution was to lower the temps allowing the animals to shut down there metabolism, place them in a well hydrated bin and forget about them for weeks. In this condition the lizard would sleep as if hibernating allowing healing in a stress free environment, no weight lost was recorded and only one or two met-blue application was needed.
This said I can only express what I would do if I was in your situation, by all means this should only be attempted if you are ready to take full responsibility for any possible outcome. Thru the years iv been in more cat fight with veterinarians then I care to remember, nothing I do fits there mould, nevertheless I keep succeeding where they keep failing simply because I am the keeper and know my animals, I can and will put the time and efforts, I will make the observation and correct any situation on the spot, most vet are to busy to waste countless hours on a lizard, we do it out of passion and put our hart and sole to it.
I would fine the right temp where this uromastyx stop all activity and allow it to rest in a dark bin filled with dirt until fully healed, It can take weeks maybe more? But nothing stops you from checking on progress when ever you feel the need, uros have been hibernating for millions of years no need to worry.
One last observation, sand is abundant in my area, at one time I had many enclosures with only sand in them, eventually I realised it didn’t work for my animals, in my case the reason was simple, sand is sterile for ground braking critters like dung beetles and other organism that feeds on faeces and other wastes, on the other hand it’s a good nasty bacterial incubator (unless kept very dry) however then dry faeces becomes dust and still affects the host, my solution was to add dirt to the sand and sphagnum moss (not peat moss) to help in holding borrows. This helps in hydration control and make everything work well for me.
best of luck!