I use bluing, corn starch and simple green. :) I also use downy clothes washing detergent to keep my horse's mane and tail tangles free. (use it as a wash first and than apply more for it to soak into the hair. Don't use on the mane if you want to braid!) It also gets all that useless dirt out of your horses mane.
Hope this helps!
"Horses are like a drug." - Libby