Projector texture swap

[Splankton]

I've ran into a problem with using a projector. I'm trying to swap from one texture to another, of the projector using set main texture in set property.
Problem is, only the 1st texture is shown, not the one I'm trying to swap to. Is this a limitation of the projector, or is there something I'm missing ?

[Splankton]

I think the reason why I can't change the texture is because the shader the projector uses doesn't require a main texture like other shaders,  its properties uses a cookie or shadowTex or something like that,  so the problem is I can't access that property from set property. 
Anyone know of any other way?