I find blackouts ineffective against algae in general... I mean they work for me if I hold the algae in the dark for months at a time. And even then, blackouts have no effect on the spores formed.
For hairalgae in general, everyday toothbrush, coupled with amanos and other consumers of this algae. If conditions are good for plants and you harass it daily it will go away. For have infested patches of moss maybe H2O2 would be somewhat effective.