Agitation isn't about "conversion" its pointing the way. You can't make anyone "see the light." Best you can do is suggest that there is a light and let them seek it themselves.

I'd say, if you can make any headway in a short time that's a good sign. Agitating to an open person is never a waste of time. If they will allow you to give an alternate opinion they aren't really fascists are they?

Plenty of skin heads see what is wrong with the world and think that there isn't any way to make it better so they might as well be on the top of the pile by being the most ruthless.

I think a persons political stance only really gets changed when material conditions are disrupted. Things they have read and heard influence where they go to understand their new situation.