Bleach water wouldn't kill coccidia anyways. Only an ammonia solution and some QUATS will actively kill Coccidia. However, heat will work too...assuming you can fit that thing in your oven. Put it in there @ 285 degrees for 2.5 hours.
I don't know how you plan on disinfecting the tank, but you are pretty limited in your options when battling Coccidia. A 10% ammonia solution is your best bet. If you have access to a good QUAT based disinfectant (Roccal D, 3M Quat, Zoo Med Wipe Out), that will also work. These are typically rinse free disinfectants, which is a plus. You could use them on the root too, just need to spray it down with water afterwords.
The problem with Coccidia is the oocysts. They have a hard shell, which makes them virtually immune to a whole assortment of disinfectants. They can even survive being boiled for several minutes. They are certainly tough buggers to kill...that's for sure!
While treating for coccidia, I wouldn't use any of the permanent cage furniture or hides. Because the nature of the infection, you will constantly be cleaning all these items...so my recommendation is to stick with disposable items until the animal tests clean. shoe boxes, cereal boxes, etc etc. Its a better alternative then constantly boiling or baking the items after every bowel movement.
You can get ammonia the same place you get bleach...just about any grocery store, walmart, target, home depot, etc. As for the cage disinfectant, post the brand and I'll see if I can track down its composition. Honestly though, your best bet is a 10% ammonia solution applied for 20-30 minutes (1.5 cups ammonia to a gallon of water...close enough ). Then rinse REALLY well, as its pretty noxious stuff. Might want to do this in a well ventilated room with the dragon far away. IMO...its only a tad more noxious then a 10% bleach solution, but some people are really sensitive to ammonia. Also, never mix ammonia with bleach. Not implying you would, but I figured its something I should say anyways. Mixing those two chemicals will result in a noxious and extremely toxic gas.
If you end up getting a QUAT based disinfectant, then follow the recommended dilution ratios and contact times. For Zoo Med Wipe Out 1, ignore the recommended 5 minute contact time, and leave it applied for 15-20 minutes. That product is already diluted, so don't mix it with water.
When disinfecting, you'll need to remove any soil before spraying the solution. So any dirt or feces should be scrubbed clean with soap and water. These kinds of things can provide a nice hiding place for the pathogens you are trying to kill.
This is the cleaner that i have here at the moment.
I'll be going out to see what else i can get
I don't have, and never have used loose substrate so there is nowhere to hide, and as soon as they have pooped it gets taken out and wiped straight away.
That is a QUAT based disinfectant, so it should be effective against coccidia. Spray on, and let it sit for 15-20 minutes. Wipe dry, and I believe that product is advertised as a no rinse product...so just wait until any fumes are gone and return the dragon to the enclosure.