http://www.reptilerooms.com/index.php?categoryid=23&p142_id=149&p142_dis=3&p142_template=Simple
Note this paragraph specifically:
"Nolvasan or Quat cleaners are not going to kill coccidia oocyst, but hot water will, hot water will also kill flagellates when other cleaners will not. So if you have a steamer at the house, that is more effective than a cleaner or bleach water. The cleaners like Nolvasan and bleach water, will kill some bacteria, fungus and virus that the dragon may be more susceptible to while on meds, or in an otherwise immune weakened state, but is ineffective to the coccidia. If you do not have a steamer, take almost boiling water in a pan and wipe the tanks down with it, also soak the basking areas and other furnishings in it. (tongs or gloves work so you do not burn or hurt your hands."
http://www.beautifuldragons.503xtreme.com/Disinfectants.html
Note this paragraph:
"Chlorhexidine - (Nolvasan, Virosan, Chlorhex, Chlorasan, Phisohex, Hibitane, Hibistat)Disadvantages: moderate cost, long contact time, poor efficiency against most viruses, and not effective against Cryptosporidia, Giardia, coccidia, mycobacteria, bacteria spores, gram-positive bacteria including Pseudomonas (except Virosan, it will kill Pseudomonas), not very effective in the presence of organic debris, and hard water makes it less effective."
Nolvasan (Chlorhexadine) is not effective for use in killing coccidia/coccidia oocyts, as Lance mentioned previously.
Bleach/water mix will kill some, but is not as effective as the amonia/water mix. Boiling water or a steam cleaner are very effective.