A method of scrubbing lower mass sulfides with a sulfide scrubbing medium capable of regeneration. The sequential order of gas flow through three vessels is altered. A first of the three vessels is maintained in a scrubbing mode, scrubbing to breakthrough sulphur from the gas that passes through it. A second of the three vessels is maintained in a conditioning mode. Sulfide scrubbing medium in the vessel removes any residue of sulphur from the gas while being conditioned by such limited exposure to sulphur. A third of the three vessels is maintained in a regeneration mode. Saturated sulfide scrubbing medium in the vessel removes excess oxygen from the gas while being regenerated by such exposure to oxygen.