I think you misunderstood the type of pressing sheet they were demonstrating. Fusible doesn't stick to the silicone ones.
There have been a couple of recent threads on the boards about removing fusible from fabric. One that works is to place a paper bag (plain part, not logo part with dyes) on top of the fusible and iron. This may have to be done multiple times. Apparently the fusible prefers sticking to paper than to fabric.