Vehicle required.
Wintergrasp:
Drive a vehicle preferrably demolisher to the relic gate. Stop and quickly position your self paralell to the door. Wait until the vehicle is destroyed. Your character then will be ejected from the vehicle, through the door and into the relic chamber. Easy cap.
Strand of the Ancients:
Drive vehicle to Gate (if successful) keep running into after reaching it. Moments before getting destroyed move to the left passager seat. You should get thrown to the oppisite side of the gate unharmed. Click on relic to capture.
I've done this many times, and I can confirm it works with both Alliance and Horde.
I grandly apologize if this is a re-re. Please post the link to the thread that shows this method.