Did the Messenger, may Allah bless him and grant him peace, chew frankincense (gum) or apply kohl (to his eyes)?

The Prophet, peace and blessings be upon him, applied kohl and commanded its application with ithmid (antimony). It is reported that he had a kohl container with which he applied kohl every night, three times in each eye. As for chewing frankincense (luban), there is no report indicating that he did it or abstained from it. His not doing it does not indicate its prohibition or disliking, just as his doing it would not indicate its Sunnah status. His natural actions are not considered part of thenah unless their specific form is intended as an act of worship.