Please try soaking your feet in a mix of borax, clay, and epsom salt. I use about a cup of each then fill the basin with enough hot water to cover your feet. You can feel "stuff" coming out quickly. Clay and Epsom Salt have drawing power but the borax seems to boost them and it's no more toxic than table salt . And it's cheap.
If you can't get clay just try the borax and salt together.
It works for me and I hope you can get some relief also.