Perhaps instead of force crouch, which as aco said would make the item shitty, there is a way to fix the model from becoming stuck, which I guess would require the model to actually walk instead of skate. Perhaps its possible instead of trying to eliminate the walking sounds per se, but instead replace the footstep sound with a new sound file that is in itself in audible.
Quite frankly, if its between force walk/crouch and invisible torso, it has to be the force walk/crouch. Yes it makes the item shitty, but it prevents the item from being used for reasons that are quite different from its intended purposes.
I hit Brett right in the feels.