Yes Grommets can be inserted in both children and adults, but it is unusual in adults.
Aged 67 conjures up very few conditions that would warrant a tube inserted abd I presume that he has had audiological work up.....hearing tests.
Wax that " won 't shift is not an indication for the insertion of a Grommet.
I hate to prejudge, but I would need to know why the Grommet was being
inserted.
It is only a minor procedure, but the fact still remains as to the indication for the procedure.