Kauffman's derivative-sliceness conjecture for slice knots

Let $K$ be a knot with a slice disk $\Delta$, and let $J$ be a derivative of $K$ associated to $\Delta$. Kauffman's conjecture. If $K$ is a slice knot via $\Delta$, then $J$ is a slice link.

This is the converse of the elementary fact that a slice derivative yields a slice disk for $K$. The conjecture is disproved by a counterexample consisting of a genus-one slice knot with a non-slice associated derivative.