I may overdo it. I take my plants outside and take them down to bare root, usually knocking as much soil as I can off and then using the hose for the rest. I gently clean the leaves only with soapy water (I use Dawn dish soap) and then I rinse, rinse again and just for kicks, rinse again. I repot in a fresh pot with organic soil with some pebbles on the bottom and then it’s ready to use. Some choose to cover the soil with river rocks that are too large to be eaten to prevent their chameleon from eating the soil.
The main thing is to remove any potential fertilizers, pesticides, bird poo or other contaminants from the leaves as your chameleon will be drinking from these. This may help.
https://chameleonacademy.com/plants/