The longer shedding could have to do with his care previous to you getting him. Where did you get him from?
Chameleons are dry shedders, so you just keep his husbandry the same as the rest of the time, super easy! You don’t want to ever bathe or shower a chameleon, that's old, inaccurate info, and warm water to us can be scalding hot to chams. If there is stuck shed around limbs/feet/tail/etc. causing circulation issues, that’s the only time you intervene if needed. Otherwise you don’t touch the shed at all