This ad was reproduced in a book I have called Housekeeping in Old Virginia from 1879.You can click to enlarge the image and to read the accompanying text - a portion of which I have added below.
It has been found that magnetic treatment makes the muscles and tissues more plastic and yielding, and it its argued from this that ladies who wear these corsets will have no difficulty in moulding the figure to any desired form without tight lacing. A tendency to extreme fatness or leanness is a disease which, in most cases, these articles will be found to cure. In appearance they do not differ from the usual corsets, being made of the same materials and shape. The are worn the same and fit the same but give a more graceful figure.
In place of the ordinary steel busks in front, and a rib or two at the back, Dr. Scott insets steel magnetods which are exactly the same size, shape, length, breadth, and thickness as the usual steel busk or rib. By this means he is able to bring the magnetic power into constant contact with all the vital organs, and yet preserve that symmetry and lightness so desirable in a good corset. It is affirmed by professional men that there is hardly a disease which Electricity and Magnetism will not benefit or cure.
Dr. Scott came out with all sorts of 'electrical' items from hairbrushes, to curlers. You can read more about that here. I found this somewhat intriguing, the marketing, the claims, and even the idea. HA!