I definitely think you can bring it up, but I agree that it should come from whoever is responsible for coordinating the techs rather than someone else. Write to your supervisor (or whoever arranges for the tech to come in) and let them know in general terms that their cologne is too much. I think this is like any other grooming issue.
As for the chit-chat, be a bit more blunt with him before you go to the employer. After exchanging pleasantries, just say, "Well, I have to get back to work. I know you do, too."