I suffer from non-allergic rhinitis and the only thing that has helped in the past is steroids, which have undesirable side effects.
Read up about using capsaicin based sprays (pepper) and made an infusion of cayenne pepper with hot water. After straining it, I pumped it up my nose with a neti pot (actually an Emcur douche). Wow! That bloody hurts!
However, a short time later, my nose stopped dripping and I could breath through it again. Itching has gone and head feels much clearer - well worth the initial discomfort. You can buy "Sinus Buster" online which is about £12 but my way is much cheaper, albeit messy