As long as he will open his mouth I would keep dripping a little water into it until he won't open his mouth. My Arnie became impacted and that's what I had to do. I didn't have a shower plant so I did it in his cage (made a mess but that's what paper towels are for) I sprayed, but he wasn't drinking. I dropped water from a baby medicine dropper. Eventually he hissed at me and I was able to get some water in him. Once the first water went in he just opened his mouth up and I gently put a little more. We did this for awhile until he stopped opening his mouth. The next day he pooped big time. He is now pretty well hydrated, but he was not really dehydrated, just hadn't pooped. I guess maybe you'll have to decide if you want a chameleon or spend the money for a vet visit.