It may be worth a search, as i think this has been covered before.
I don't know of any conservative measures that really make a difference in glue ear, other than avoiding cigarette smoke.
Physiologically, I can't see why an insertion of a grommet would cause your son to have problems, indeed he's likely to suffer less than Joe Average. (Isd hearing acuity affected? I'm not sure.)
I'm wondering if problems may start when the grommet falls out, (as they tend to have a habit of), or is removed.
Have you told your specialist about your sons career intentions?