I have Svart Hona too. However, I put mine in the coop for quite a while, with their food and water, so that they understood where "home" was, and they have always returned to the coop at night. My set up allows me to actually herd them in at night when I want to, so even if they did not go in the coop, I'd be able to herd them in. They always go in so it's not a problem, and I lock them in at night to keep them safe.
I guess I would suggest to catch them at night (way easier than trying to catch them in the daytime because they can run like the devil) and put them in the coop, with food and water, and leave them locked in there for a week or maybe even two weeks. HOWEVER. That is ONLY if you have enough room in your coop!
My feeling is that this is a good plan due to the fact that if they are locked in the coop at night, there is less chance for a predator to get in there and "get" them. I've been wiped out by raccoons before... my coop is VERY sturdy and tight to prevent that happening again.
I want to emphasize: you have to have enough room in your coop to be able to lock them in. Don't do that if it's a tiny coop and a lot of birds.