I would give your passion flowers a hard pruning and train them to grow in the opposite direction to your azales. Another option would be to move your passion flowers. But, pruning and training should probably do the trick.
I'm a huge fan of passion flowers. Did you know that they are edible?
Also, Passion flowers are what are termed "primitive" flowers because in order to be pollinated, the insect needs to literally walk around in the flower which, consequently destroys the flower. (Though, I'm not fan of the word "primitive" let us just called them different.)
Oh and no, we don't recommend sprays and other such synthetics for inhibition of growth. Pruning would be your best bet.
If there were such a spray out there ( and I don't think there is) it would most likely inhibit the growth of your Azaleas as well. Not to mention that if it were to drift in the wind, it would inhibit the growth of other plants.
Anyway, happy gardening.