I thought this was the private flying bit of the forum, not the airliner bit?
As Sapco 2 said the crossed controls technique works on every aeroplane I have ever flown from Tiger Moth/Chipmunk to the Boeings.
Are you suggesting that private flyers have nothing to learn from those that fly the heavy metal?
My Boeing/Douglas autopilot doesn't slip,
I presume it's a Douglas autopilot rather than a Boeing one?
have always been told that you must crab in the big jets
I was also led to believe one such reason was if you use a wing down approach you might drag an wing mounted engine pod on the ground at the bottom.
It's not a wing down approach. You are picking the wing up with opposite rudder so that the residual bank is less than 2 degrees. You are more likely to dent a pod in a kick-off-drift scenario that goes wrong.