Fenugreek tea may help thin out the mucus so that it will move one way or the other...be sure to check for interactions with medications first (ask your pharmacist and your LLMD).
Something else that seems to help me with the post-nasal waterfall and sinus congestion is a product made by Peaceful Mountain called Nasal Rescue - it is a colloidal silver nasal spray. I get it at a local health food store. I have no financial connection to this company/product...just am a happy customer.
Another thing that may help is Pine Cone Extract. My Brother has horrendous allergy attacks from mowing the grass, but last weekend he mowed the grass and got no symptoms at all because he'd been taking the Pine Cone Extract. Amazing, since he's had life-long severe sinus allergies, gotten allergy shots, etc., and still struggled with the sinus allergy symptoms until trying the Pine Cone Extract. My Husband finds Pine Cone Extract helpful for his food allergies, also. We get the Pine Cone Extract at a local health food store.
I hope this helps...take care,
Chronic Lyme Disease, Chronic Bartonella (clinical dx only), Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, chronic Lymphopenia, etc.; G-Tube; Currently weaning off TPN.
Meds: Pulmicort, IV Doxycycline, Heparin (to flush PICC line), Claritin, Singulair, Domperidone, Colloidal Silver (topically & nasally), probiotics, Liver support herbs, Ailanthus, digestive enzymes, homeopathy.