Thank you for your question.
If he is using Q tips more frequently, there is a possibility of infection inside specially when it i assoociaed with strong malodorous smell.
He msut be examined by a local physician in order to confirm this and treated for it accordingly.
if it is infection, he will need to be treated with antibiotics like ciprodex or corticosporin drops.. if it is fungal infestation, it needs to be treated with topical antifungals.
He must not use q tips or anything to clean the ear.
Yes. in case of ear, it is possible.But as I said, it can be confirmed only upon clinical evaluation . There might be other causes of bad odour as well which can be figured out by direct examination.