Rotational echo double resonance (REDOR) is used to analyze ionic motion in tetrahydroxoborate sodalite, which can be regarded as a model system for rotor phases. The motional averaging of B-11-H-1 and Na-23-B-11 dipole interactions probes both the reorientation of the tetrahydroxoborate anions and the sodium motion, respectively. To this end, REDOR data from multiple-spin systems with quadrupolar nuclei have to be analyzed quantitatively, and the underlying theoretical model is presented. The results show that simple Na-23 NMR line narrowing analysis can lead to misleading conclusions, and the REDOR method is a valuable tool to investigate local motion in ionic systems.