The corkscrew manoeuvre was evolved as a defence against radar equipped night fighters or those operating visually (Wilde Sau) on dark or poor vis nights. Bearing in mind that RAF heavies only operated at night until very late in the war. The idea being that it was difficult for the fighter to pick up the change in direction quickly enough and ended up swinging around like a ball on the end of a string. The manoeuvre could be quite effective. A German night fighter pilot under interrogation said that once he followed a corkscrewing Lancaster for half an hour and never once got into a position for a burst. The success depended of course on the gunners sighting the night fighter early enough - not easy. When the Germans started to use the upward firing Schrage Musik installations, this became even more difficult
I cannot believe however that in daylight or bright moonlight, a fighter with its much greater available roll and pitch capability would have difficulty getting a sighting solution. The only tactic then I would have thought would be a last second hard turn towards the fighter to maximise the deflection angle and give the gunners a chance for a shot.
The idea of the day fighter affiliation practices was for the bomber crew to practice their handling and crew coordination and for the fighter to practice his deflection estimation.