Does anyone know what the best remedy for Catarrh/mucus build-up is?

You're wanting your nose to run.ok. Try treating the symptom beside
1) hot steam, perhaps beside eucalyptus oil contained by it
2) Vick's Vapo Rub as directed
3) my doctor prescribed Guaifenesin, which I found in over-the-counter meds as all right
4) hot and spicy foods
Try treating the cause next to
1) vitamins A, C and E
2) grape seed and skin extracts
3) a appropriate multi-vitamin and
a good herbal formulation
4) crude or frozen fruits and vegetables
Also consider laying rotten mucus-forming products, such as milk and cheese, while drinking more fruit juice and wet.
Drink plenty of fluids.
Eat Garlic and something else yucky, but I forgot the other thing, I'll gag if I remember.
Speaking from limited experience, sex is great for clearing the sinus's!
Drink lots of fluids and avoid dairy products.
Use a few drops of eucalyptus grease on a tissue and inhale. Also you might try holding your nostrils tightly shut and then blowing complicated while still keeping them shut tight. It may not work the first time but after a few goes, you should perceive a 'popping' in your ears and that will be the foundation of all the mucus draining away. Sorry to nouns so disgusting but it really works for me when I get sinusitus. Hope it works for you
Eat foods that enjoy a lot of chilli added to them, the hotter the better.
I would stongly suggest avoiding dairy products as they can aggravate and sometimes create this condition.
Any clensing and detoxifying foods and drinks will help too: green leafy vegetables, garlic, green tea