I frequently use D76 1+1 with hangers and HP5+. I never have any streaking. I agitate initially for a full minute, but initial immersion is straight in, very quickly. I agitate by bringinging the hangers up, tip 45 degrees to the right. Submerge, bring up and tip 45 degrees left. Submerge, continue. The only streaking problems I've had with any film/developer combination were when initial agitation wasn't long enough.