Q. If I put either one (of the mint oil and eucalyptus oil – see question 2758 above) into my nose, both to enjoy the smell and the cooling feeling they provide, but also because it clears the sinuses, do I make a brocho?
A. Shulchan Aruch (O.H. 226: 2) rules that if someone eats an aromatic food when his intention is mainly the eating and not the smelling, even if it does provide a pleasant smell, one does not recite a brocho on the smell.
In your case it would seem that an important part of the use of the above oils is their aroma. If that is the case, it stands to reason that a blessing should be recited.
Horav Shlomo Miller’s Shlit’a opinion is that if there is an intention to have pleasure of the smell a brocho should be recited.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit”a