Radon daughter decays continue to limit the sensitivity of 10 GeV — 10+ TeV direct dark matter searches, despite extensive screening programs, careful material selection and specialized radon-reduction systems. While these techniques form an essential basis for rare-event search experiments, we seek a fully-efficient event-level tag of radon daughter backgrounds. For detection instruments based on liquid xenon, a means to obtaining this lofty goal may lie in crystallizing the xenon. Then, experiments would record unique (E,x,y,z,t) signatures for the problematic nuclear decay chain steps and be able to reject beta background events. A further benefit of this approach is the expectation that crystalline xenon would exclude the ingress of emanated radon. I will present recent results on the instrumental performance of a dual-phase (crystalline/vapor) xenon time projection chamber, preliminary results on radon exclusion from the crystalline state, and a brief assessment of the promise of this technique for reaching the neutrino detection limit.