My experience and learning is that laser works just in light skin and dark hair but eventually hair will grow again and people under just laser always need "redoes" from time to time.
Electrolysis is more radical and work.with any asking ir color hair, for that reason as it was said, is more expensive.
I'd been so far 8 months of 2 hours weekly, (all on one session) an just now I'm seeing real.advance on the upper lip. Upperlip is the more painful and sensitive area. In my case this area is the one with more dark hair because the rest is gray with mostly white hair, after shave no dark shade so my focus has been the upperlip and next will be the chin.
Other areas, around the lips had been treated and in two sessions hair didn't grow again, as well chicks.
I'm lucky a d my health insurer pays for it so no money out of pocket just to drive 30 miles away that's the nearest electrologist that works with insurance because they pay less.
After had a really thick, abundant and black moustache that grows a bit around the nose too, today before electrolysis I count 17 thin hairs that took 16 minutes to treat by the electrologist and she found s the rest of the 2 hours around the chin just attacking the dark hairs (btw, she is so nice and understand my needs because has treated so may transgirls)