I had been going to a salon with a beautician that offers electrolysis (using a Sterex system) for several months. I thought "so, this is electrolysis".
But recently I went to a different person who only does electrolysis. It's a completely different world, and seems much more effective and thorough. Here are some possible "warning signs" from my experience:
Is a bright light and magnification used during treatment? The electrologist should be using a high power magnification lens or special glasses, not just regular eyeglasses.
Is the electrolysis machine "muted" so that it doesn't beep during treatment? This is the feedback the electrologist is supposed to have to know if the machine is actually working, so be suspicious if it's muted.
Are there only "commercial" qualifications (e.g. "Sterex Company Certified"), instead of an independent association? In the UK the person should be a qualified and listed by the British Institute & Association of Electrolysis.
Is the treatment fast?
Do you feel hairs being pulled-on much of the time? They should slide out easily without any tugging sensation, and if they don't, the electrologist should be treating them again.
Is the electrolysist recovering each hair and inspecting it, or just brushing it away? They should be looking at the hairs and keeping them on their glove or a tissue to know how deep they are rooted and how effective the settings are.
Are they treating each hair while moving the needle up and down the follicle, or just "stab and treat"? Maybe this is just a technique with "Flash" electrolysis, but it seems more effective.
Does the electrolysist work with doctors and health insurance/government health bodies? If not, they probably don't see many trans clients. Insurance companies and doctors only refer to electrolysists that have the right qualifications.
This is just my experience and I'm not an expert.