Frightprops Grime works great. Another Option is Allen Hobbs Method Using Clear Poly Glue, Food Coloring or the best method is Clear Poly Glue and Smoothe On's too strong Tints . Also check out Allen's ICE You Tube Video. His is with a green tint looks like Snot or Ectoplasm Awesome looking stuff I am making a batch today for a scene to try it. Very Cheap and it looks like it will do the job. I tryed His Blood Formula just because I am Cheap and it looks awesome. The Smoothe On Tints are a little pricey but it only takes a few drops so it goes a long way. I added a liitle brown and green to my blood. Try it you will love It It is cheap and looks great.