A method for protecting a cable splice connection including a cable, the cable including an electrical conductor surrounded by a cable insulation layer, includes providing a splice body assembly including: an electrically insulative, elastomeric splice body having an interior surface defining an interior passage; and a layer of a conformable medium pre-mounted on the interior surface of the splice body. The conformable medium is a flowable, electrically insulative material. The method further includes mounting the splice body assembly on the cable splice connection such that the layer of the conformable mastic is interposed between and engages each of the interior surface of the splice body and an opposing interface surface of the cable insulation layer.