Baytril needs to be injected every 48h to be effective. Every 5 days will just prolong the disease process and make the bacteria more resistant.

If the Baytril is the lower concentration, it isn't as likely to cause burning/scarring. Are you sure it's 0.2ml? How much does the snake weigh?

If you can get some sterile saline and draw up 0.1-0.2ml in each syringe with the Baytril right before you give the injection, that will help prevent scarring and stinging.