LWRP - shader graph - transparency for distortion

I’m trying to create heat distortion in my LWRP project.
I’ve started out by creating a simple transparency shader in shader graph, so that whatever is behind the gameobject is rendered onto the object, giving the illusion of transparency.
My setup is linked below. I’ll be applying noise as an offset for the actual distortion.

My issue is, I can still see the object due to the discoloration, see image link . Any idea how to make this actually fully 100% transparent as if it weren’t even there in shadergraph?

shadergraph setup

material applied

the PBR master surface type is set to transparent.
Any ideas?

I was able to get the effect i wanted using the Unlit master node, rather than the PBR