The Auto-Rx will liquify the sludge and carbon build-up in an engine and move it to your full flow filter.
Teflon additives in an engine tend to crust up in very small to larger crusty build ups. This is caused by the heat of the engine. I think Auto-Rx will move the smaller particles, but the 1/4" and larger crusty build up is to heavy and generally sits in the bottom of the oil pan and can only be removed by oil draining or removing the pan and cleaning.
I know this is not a scientific explanation, but having seen vehicles after using Slick-50 this is the only way I can explain it.