swollen salivary gland excretes a white stringy substance

I have been having this problem for the past 25 years, on and off and am currently right off an episode with a disfigured face and with swollen glands. I messed around with the irritation a lot which does not work for me.

Symptoms are: Itchy feeling in the parotid glands. When I start meddling with that area like massaging, pressing or scratching, my ears, and eyes, all feel itchy, irritated, allergy kind of feeling, with eyes watering....
The more I mess around, as the irritation builds up, the parotid glands start swelling faster and bigger. At this point I know that there is a block, and I can't but keep massaging till the white stringy, metal smelling, substance comes out. Sometimes there are a few strings that come out of the glands. One gland could be worse than the other. I know when I feel relieved but the swelling stays for a day or two and then subsides

Some of the triggers are: Food allergies (Certain foods with preservatives), certain fruits or vegetables that I know don't sit well with me, environmental allergies...
The reaction will start within a few hours or sometimes a day or two.

The ways I handle this are: Try not to mess around with harsh massaging as it makes the swelling worse with more inflammation (though sometimes I can't help). On days when I am careful, it doesn't get that bad. The point is for relief, the stringy substance must come out. So, what I do is some of the following till I get relief.
1. Brush my teeth and floss and gargle with Listerine. Let the Listerine sit on the cheek for some time till you can handle it.
2. When I take my shower I let the hot water fall on my face for a few minutes and with soap, for the sake of lubricating, massage the area. When the glands are warm, the stringy substance comes out easier as the duct opens up well. If that still does not work as soon as I come out of the shower, when my face is still warm, with some moisturizing cream, I massage and get the junk out.
3. Apply some Vicks Vaporub in the area to get the inflammation down, When the glands get inflamed and swollen, it gets harder to massage and get the blockage cleared.
4. Take a Tylenol/Advil/Anti histamine syrup/ Nasal spray/ suck on Ricola Natural herb cough drops. Sucking on the cough drop at the initial sign of an episode reduces the risk of high inflammation at most times. Hot fomentation helps with the inflammation too.