Alright, I figured out a way to strip off textures but I haven't tested this yet on older hardware so I'm not sure this works completely; it works on my machine but then my machine is also fine with lightmaps and the whole point was for compatibility with machines which aren't. While poring over the command reference I noticed the TextureBlend flag 0 is listed as "no texture." I tried this code and it worked:
blank=CreateTexture(1,1)
TextureBlend blank,0
EntityTexture object,blank,0,1
blank=CreateTexture(1,1)
TextureBlend blank,0
EntityTexture object,blank,0,1