How can I repair a thin crack in the bottom of a porcelain teapot?

I have a Spode porcelain teapot that has developed a small crack along the base of the pot right below the spout. I remember hearing that if you boil cracked porcelain in milk, it will "heal" the crack. Is this true? I didn't want to risk further damaging the teapot without a little consultation.
Thanks!