4 oz Melt & Pour Glycerin Soap Base 
  (clear or white)              
1 tablespoon castor oil
1/8 teaspoon vitamin E oil
1/4 teaspoon liquid glycerin
10 drops peppermint essential oil
10 drops tea tree essential oil

Melt the glycerin in the microwave, until just melted, not boiled. Add the remaining ingredients and pour into your favorite square mold.  

Then, try to get your dog into the tub!  
Good Luck....

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