You can try e-mailing her (haven't seen any posts by her in a long time).

Though the odds of a one-day cure for chronic foot swelling using herbs, exercise or any modality are approximately zero.

There apparently are some Yoga positions that affect the kidneys; I don't know much about Yoga but someone else posting here might.

Also, a family member was told by a physician that lying down (or, apparently, even elevating one's legs) assists the kidneys to operate better.

Here is a link that will bring you to a Google page providing several links connecting Yoga positions with the kidneys.

Here is a link that might be useful: Google Search Link

Numerous forms of physical exercise (including yoga) may be beneficial in people with kidney ailments (which can contribute to foot swelling).