Light Diffusers - Cheap

I've been doing basic experiments with homemade light diffusers with mixed results. The first thing that stuck out was it is time for some glass cleanings before I try to shoot through water spots again, but I did get a few halfway decent experiment pics. My goal is to remove the horrible green and red eye I almost always get when using a flash indoors with the critters. Most notably one of my dogs with gold eyes and my cat. Neither can be photographed with the standard flash on my camera, and before I buy a slave flash I thought I would play with some cheap diffusers. One was just white paper wrapped around the flash, which was okay, but not great. The better one used plastic from a make your own stencil kit. It is slightly opaque, but lets most light through, with a matte finish on one side, which bounces the light nicely. It does have a slightly yellow cast that needs to be edited out later though, so i might have to stick to white paper until I'm interested enough in something else.