Appearing at the unveiling of the singer's double at Madame Tussauds, he said: "We're going to take this one home with us and take the real one back."
He added: "This one does what she's told and doesn't move."
Mitch, who was accompanied by ex-wife Janis, insisted that his daughter's addiction problems could be used in a positive way by others in similar circumstances.
He said: "I would hope as that time goes by she's being a positive influence, showing how these problems can be overcome.
"So perhaps she can go from being a negative influence to a positive one."