McKenzie's Prone Push ups with overpressure -- in contrast to Mulligan Concept's self lumbar traction

I had a co-therapist who recently got certified with the McKenzie method for cervical and lumbar dysfunctions and I thought it was a rather agressive method but (effective) in centralizing symptoms (which is what we all want right??). One particular method I have tried and found effective was the Prone Push ups with clinician overpressure. --- Patient does the prone on hands push up and while the PT pushes down on bilateral lumbo-sacral spine.... very hard, and I would hear patients grunt coz of the hardness of the technique... McKenzie stated: If you could centralize symptoms within two weeks, you have 95% chance of achiving full centralization. I thought there was rather a good statistical data attached to it too.

Mulligan's concept is almost a Prone push up except the patient places his/her hands at the waist level and NOT at the chest level! --- That's self lumbar traction....