There is evidence from flat worms that electric fields is how cells naturally move in the right directions with purpose. However they produce the fields chemically via ion gradients.
IMO the issue is with unhealthy people, things like poor circulation reduces the body's ability to produce the natural ion gradients and thus why the external electric field helps.
There's a very cool researcher who used this method to create flatworms with heads (or tails) on both sides. https://www.cell.com/biophysj/fulltext/S0006-3495(17)30427-7
IMO the issue is with unhealthy people, things like poor circulation reduces the body's ability to produce the natural ion gradients and thus why the external electric field helps.