The Homepage of the german professional association Elektroepilation e.V.
Here are also questions answered that might interest you.
Fachverband Elektrologie (in German)
The Homepage of the association Fachverbandes Elektrologie e.V.
Stiftung Warentest: Haarentfernung (in German)
Stiftung Warentest presents the different methods in comparison, with electrolysis being named the only procedure for permanently permanent hair removal (in German).