Question about the foot pads:

hi

I have just started using the Body-Pure foot pads. On both feet resulted in very dark residues after a night's use:
My question:
1. Has anyone here used for 30 days and found the dark residue getting less & less till none is seen, and did they find corresponding health benefits.
2. Can you walk with the pads on?
3. Has anyone noticed any side effects?
Thanks
Best Wishes,
Dan