Do you have a source for that? My understanding is that otherwise inadmissible evidence can be used in a grand jury hearing, but you are still free to "plead the Fifth" in front of a grand jury without being held in contempt. Meaning, if you were previously compelled to self-incriminate, that might not be admissible in your trial, but it would be admissible in a grand jury hearing (same for the Fourth and Sixth).

Now, the Fifth only guarantees protection against self incrimination, so I assume you could still be held in contempt for refusing to incriminate others.