The KOH normally makes a soft, somewhat sticky paste, not anything that can be made into hard bars.
You could dilute this into liquid soap that you use to wash your hair, but it probably has a large superfat (or at least, more than the 2% or so that is typical for LS). Unless you add a solubilizer like PS80, this SF is likely to separate from the rest of the diluted soap, and will appear as a layer of oil on top of the soap, or a white, kind of waxy foam.
Another option would be to make a new batch of shampoo bars with the correct lye, and mix in enough of the heated and softened paste to make dual-lye bars. Depending on how large of a batch you made, it will take you awhile to use up all the paste this way.