Just hide the geoset using a geoset anim. If you use magos go to geoset anim manager create a new animation assing the geoset you want tick animated > alpha and in the list write something like:
0: 0
1000: 0
and set the interpolation to linear.
The starting 0 and 1000 being the starting and ending point of your sequence that you want the geoset to be invisible in.
Technically for what you wanted to do you need really any in-game texture that has at least a single pixel to be completely transparent. And wrap everything with just that single transparent pixel.
Your way won't hide the geoset though just make it entirely transparent meaning that the geometry will still behave as if it was there, render the polygons, use the geometry for walkable destructibles and so on.