I set up my quarantines in a separate building.
The professional standard is three clean fecals- once they have three in a row over several weeks' time, they should be good to go. Allow 2 weeks minimum between fecal exams for parasites' life cycles. Some eggs may remain after the medication, and these need time to hatch and be killed as adults. However, some vets are not as versed in exotic parasites, and can give false clean results if they don't know how to look for certain oocysts. A really nasty one WC chams can get, easily contracted from contact with other reptile species' feces during importation/holding, is very difficult to find in a slide unless the technician is a specialist: Cryptosporidium.
It is wise to get 3 clean fecals from CBs, as well, because even well-kept animals can harbor low levels of parasites from farmed insect prey. Those low levels bloom and take over after the stress of shipping, new territory, new owner, different water...