Make a Model Invisible

I have a model that I want to make invisible. It will be used as a walkable platform. I tried deleting the materials/textures using Magos but that just froze the editor when I tried to assign any object to it.

The reason why is that the model has an issue with extents in-game. When I assign it as a walkable destructable, then moving my camera slightly off its view will make it disappear (a sign of improper extents). If I assign it as a doodad, that problem doesn't happen. Thus, my idea was to make the walkable platform invisible and place the doodad version on top of it (so it would essentially have the same effect, but the model wouldn't disappear). And yes, I did calculate the extents in Magos.

Anyone know how to make the model invisible (and able to be assigned to an object in WE) or any ideas on how to fix the issue with extents?

EDIT: I came across a temporary solution for my map but it would still be useful to know how to make a model appear invisible. By this, I mean in a similar fashion to the invisible platform models in wc3. (Doodads\Terrain\InvisiblePlatformSmall\InvisiblePlatformSmall.mdl)