What is the effect of inducement for an accused to confess to a crime?

"Of course, after an accused has once let the cat out of the bag by confessing, no matter what the inducement, he is never thereafter free of the psychological and practical disadvantages of having confessed. He can never get the cat back in the bag. The secret is out for good. In such a sense, a later confession always may be looked upon as fruit of the first. But this court has never gone so far as to hold that making a confession under circumstances which preclude its use, perpetually disables the confessor from making a usable one after those conditions have been removed." United States v. Bayer, 331 U.S. 532, 540-41, 67 S.Ct. 1394, 1398, 91 L.Ed. 1654 (1946).