Aerodawg Inhaler

So recently my Basset has develop a dry heav/hack, if you will, that when we took him to the vet seemed to be due to a respiratory issues. His Eosinophils where off the roof and his lung xray showed his lungs bring very cloudy. They prescribed him Prednisone pills which help the issue but they advised he will need a steroid goong forward (which im hoping is not true). But one he was better they want to switch him from a pill to an inhaler 2 times a day. I went through the weining process on the pill and have been trying to get him to use the inhaler but hes 100% not having it… i tried enticing him with treats, i have put treats or aroma scented things to try and get him comfortable with the AeroDawg on, ive tried using cups (styrofoam, solo, paper) to give him more area to put his nose in, but he completely refuses. I tried to feed him treats through the cups to get him use to them but he refuses. At this point the only thing i can do is try and give him treats from my hand and spray it while hes eating pretty much right at his nose (he hates it too). Hes too arrogant to chase or try and force it (and I really dont want to since we will probably be doing this til he passes).

Any suggestions or tips?