My sports physician Dr Rob Reid (who knows everything there is to know about joints, tendons, bones, and such) recommends using a baking soda poultice on swollen and inflamed joints. I find this quite soothing on my sore knee.
He says : "A poultice using bicarbonate of soda is used to decrease the swelling in and around a joint or draw out fluid or oedema from under the skin. The joint swelling may be because there is fluid within the joint, or that the covering of the joint (the synovium which holds the fluid in the joint) is "waterlogged" and this produces a boggy swelling of the joint."
Here's how to make one!
1. Gather your equipment : a bag of baking soda, some water (warm or cold, up to you), a mixing spoon, a glass bowl, and a piece of scrap fabric (old shirt / t-shirt etc).
2. Mix roughly 2 cups of the baking soda with enough water to make a firm paste, roughly the thickness of bread dough. It should be soft and moist, but not runny.
3. Place the lump of baking soda onto your square of fabric.
4. Tie up opposite corners, to make a neat little bundle like so. There should be just one layer of fabric under the poultice.
5. Sit or lie down for an hour, with the poultice sitting or lightly strapped onto your swollen knee, ankle, wherever ... I usually keep a face washer or towel handy, as it can drip a bit.
After the hour is up, put the baking soda mix into a lidded container, rinse and dry the fabric, and reuse the next day (just add a bit more water to get the paste consistency again).
Dr Reid says you should refrigerate the poultice, and replace the baking soda after about 3 or 4 uses, but really, I don't see how that would be necessary, as it's never going to go off ... I've used the same batch of un-refrigerated baking soda for more than a week without problems, it still fizzes slightly when I add water.
He goes on to say : "The bicarbonate of soda poultice will draw the fluids out of the joint over a period of time, and this commonly takes 7 to 10 days, especially for a joint that has a boggy swelling for more than 1 or 2 days. The poultice can be used in association with any other treatment that is being used, and does not cause any skin problem."