In the soluble state, catalyzes glutaredoxin-like thiol disulfide exchange reactions with reduced glutathione as electron donor (By similarity). Can insert into membranes and form voltage-dependent chloride-selective channels. The channel opens upon membrane depolarization at positive voltages and closes at negative membrane voltages (PubMed:37838179). May play a critical role in water-secreting cells, possibly through the regulation of chloride ion transport (By similarity). {ECO:0000250|UniProtKB:Q9N2G5, ECO:0000250|UniProtKB:Q9Y696, ECO:0000269|PubMed:37838179}. This is the function of ENSG00000159212 (CLIC6, CLIC family member 6).