Welcome and thanks for your query to HCM.
If a dermatologists say to the patient that the best method to get rid of grey hair is electrolysis or Electroepilation then have the same meaning. So the very first thing you should understand is all the term used by you whether Electroepilation or electrolysis - are actually synonymously used by us.
Now to clarify - electrolysis means removal of hair roots or small skin blemishes by the application of heat using an electric current and electroepilation means use of electrosurgical methods, such as electrocautery or diathermy, for destroying hair follicles.
You can understand by above definitions that in any of the way we are going, the main method is actually destroying the hair root by electric current which generates heat and thus the hair root gets destroyed.
For your problem of white hair the best method is the same as discussed above, and in expertize hands it can be done in single sitting or may be done in multiple sittings and is definitely a permanent method of grey hair removal
Hope the information will help you.
Dr Sanjay K Kanodia