Oh walmart won't have cholorohexadine.
Go to any animal supply stores (if there are farms near you), otherwise look around online, or you could spend 30$ on it here:
http://www.reptilebasics.com/Chlorhe...n-p-16138.html
Personally I dislike the pump dispenser (it likes to drip).
As for scale rot:
http://www.ball-pythons.net/forums/s...archid=1015908
look through those threads.
As for length vs tank size the tank size should be no less than 1/2 his length (not in gallons but in length)
As for general care:
http://www.ball-pythons.net/modules/...warticle&id=59