everything has probably leached thru the soil by now (if it has been exposed to rain or regular watering) so that should be OK. The only concern now would be insects, earthworms, slugs, etc. that have taken up residency in the pot (they can gain access from drainage holes). Most would probably be harmless to your cham, but to be on the safe side I would suggest repotting it. You can also be bringing in whiteflies, aphids, etc. which will not only become a pest to the plant it is on, but to any other plants nearby. I'd give it a good blast with the hose and repot - but that's me 
lele
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0.1 Veiled Chameleon - Luna
1.0 Beardie - Darwin
0.2 felines - Kyndra and Líta
0.1 African Clawed Frog - Skipper
0.3 Mad. Hissers (2 died ;(
0.1 Chilean Rose Hair Tarantula - Rosa Leigh
0.1 Goliath Bird-Eater Tarantula - Natasha
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