Finite residuality of involutory quandles of knots

Let $D$ be a knot diagram, and let $IQ(D)$ denote its involutory quandle. An involutory quandle is trivial if it consists of one element.

Involutory quandles are finitely residual. If $IQ(D)$ is non-trivial, then there is a finite non-trivial involutory quandle $Q$ and a surjective homomorphism

$$IQ(D) \twoheadrightarrow Q.$$

This is presented as equivalent to the finite countermodel property needed for the proposed unknot-detection programme to become a decision procedure; the source gives no resolution of the conjecture.