Hooka Dancer's advice is excellent and safe. If the man has concsiously decided not wear colognes, you may wish to leave it at that!
L'air du Desert...? For someone who does NOT use frags?? Go ahead...if you want to loose him forever.
Something more subtle and masculine perhaps: Givenchy Xerius, also referred to as Xerius Black and opposed to the overly sweet Xerius rouge. If you're lucky you will still be able to find the immensely chique black bottle across the border in Mulhouse / France. There you could also still find Dior's Jules which is not sold outside France. Good for his age group, not over the top but a cologne with a smell, still at their old prices.
Very suitable for the man you describe, and made with a good feel for Swiss customers, are the LesNez scents: L'Antimatière
for an easy entry into the fragrant world (he won't smell a thing), the Unicorn
for a more intellectual, the Lion
for a warm hearted man! They are inobtrusive and recommendable also to the office, I would say. Tauer and LesNez will send you samples in no time. If Tauer, you may wish to ask for Orris also, call his friend at the bookstore (Spiegelgasse).
You may find it, and some of the others nice on yourself