Thought I'd add my experience. I have lymphedema in both legs, but my left leg was the worst by far. About a month ago it swelled to a tight drum again, was fiery red, incredibly painful and the skin felt scalding. I could barely walk. I was desperate. I tried the cabbage poultice, but it caused fierce itching. I mean FIERCE! I managed to keep it on for about 6 hours 2 days in a row, but I thought I would go out of my mind if I had to endure that daily.
I saw mention here of someone who was going to try castor oil. I thought I'd give it a try too. I soaked paper napkins in the stuff, wrapped them around the leg. Then I wrapped plastic wrap around to cover and duct taped it in place. I covered that with dry napkins and taped in place. Then I got a disposable hand warmer and strapped it to the most swollen, painful part of the leg. After about 7 hours I took it off and noticed an improvement and a lot less pain. Now I do this every other day and every time I'm happy with the results. At the same time I started taking Doctors Best Vein Formula because it contains diosmin. Now, my leg is almost back to normal size. I can move around and it only starts getting painful if I'm on it all day. Even then, it's not too bad.