Have you noticed that flax seeds also gel the water after, say, five minutes boiling. In fact, it gels so fast, and so firmly, that one must hurry to sieve out the seeds, if that is what is desired.
I know nothing of the Science or health benifits of boiled flax, except that vegans use the gel in cooking, as a substitue for eggs, or for texture in alternative 'cheese' and 'butter'.
There are two other soothing substances you may want to investigate.
One is marshmallow root. Apparently it helps to soothe mucus membranes. I've wondered if a poultice of it might help irritated skin.
The name of the other escapes my mind just now. It is from South America, I believe, and works up with water (no cooking?) like a gruel or porridge. If I recall the name I'll add it here.
In another direction, I've been drinking some unsweetened cranberry juice (reconstitued from concentrate...sigh) and reading about it I see it seems to help with rehydration. 'Dry mouth' seems, to me, to be relieved. I also read that it attacks E. coli, by coating it so that the cells can't stick to internal skin, etc.
I add four drops of liquid stevia to a 6 ounce glass, to help take the edge off the TART taste. Dh bought the stuff for me...bless his heart! Apparently he heard that a couple of glasses a day would help the kidneys, or urinary infections, or something...I have long-standing problems with urinary urgency, which were just lifting...thank goodness.
I've noticed some return of the urgency in recent days, but feel this may have been from the consumption of berries, which I seldom have.
Funny thing is that fruit is supposed to bring a more alkaline state, except cranberries and plums/prunes, which acidify. A long time ago I read that the urinary system is supposed to be more acidic than most of the rest of the body. So, I am unsure of what is going on. The relief of being 'in control' once more is wonderful. Makes a body feel at least 20 years younger!