Im not sure of what the advantage is, when i tried the thought did not cross my mine to shred it or anything but if there is a advantage thats a good thing!
What i did i soaked the SM and kinda wrung it out as it does hold a lot of water kinda like a mop head ; )
Anyhoot i layed a layer on bottom of plastic bakery container and then the scion then put some more on top, darn thing rooted.
What i thought was neat is when i tried just for the heck of it those expandable peat disks that i had laying around for my veggie seeds, you soak in water and they get bigger they have a netting around them so it does not fall apart, i made a hole in middle with finger and just stuck the piece of scion in it and it also rooted.
All in all it was fun watching them.