Too many undisclosed variables in your first post. Some billets may be repaired with proper procedures and some luck. Some portion of a billet can be salvaged by cutting out the bad spots, re-stacking remaining pieces, and weld again. Others could have all bad parts removed and remaining pieces used in a "canned" billet.
"Make other stuff" as you suggested; --- I once showed Jens (at his 2007 hammerin) how to use some out of the ordinary materials in a canned billet. After welding, a short section of the can was found flawed, thus cut-off. Consider little items like this necklace Jens made from that small cut-off section:
Pattern_welded_Pendant - Blacksmith Photo Gallery
I do not know if your posted question is reality or hypothetical. If reality, some stage(s) of the billet making process went wrong. Trick is to determine the hows and whys.
Hope I helped to shed a little light!