Self soothing cot naps..

My LO is 5MO.. he now sleeps in his cot for naps during the day by me patting his butt & stroking his nose.. can take anywhere from a few mins to nearly 30min (joys of teething atm).. is there ANY chance of trying to leave him in the cot to self soothe to sleep or is it too late to try it? He rolls over & gets distracted so it's hard to settle him at times.. I don't mind regardless.. 😊