A method for sealing a drop cable in a cable splice enclosure which includes an enclosure base having an open-ended entry hole for receiving at least a drop cable for passing the cable into an interior region of the enclosure for subsequent splicing, the method comprising: at a site exterior to the enclosure, providing a compression grommet assembly which includes a compressible grommet disposed between an upper pressure plate and a lower pressure plate, at least one passageway extending in alignment through the upper pressure plate, the grommet, and the lower pressure plate; and an adjustable connector assembly adapted to apply pressure to the grommet to compress the grommet depthwise between the upper and lower pressure plates (26, 28), when adjusted; passing the cable through the passageway in the grommet assembly from a position exterior to the enclosure; positioning the grommet assembly in the entry hole contained in the enclosure base, from a position exterior to the enclosure base, and passing the cable into the enclosure; locking the grommet assembly in the entry hole, from a position exterior to the enclosure; and adjusting the adjustable connector assembly to compress the grommet in the entry hole so that the compressed grommet applies a holding force to seal the grommet in the entry hole and, at the same time, to seal the cable in the passageway through the grommet, characterized in that the grommet assembly is loosely fitted into the entry hole when positioned therein and subsequently moved to a locked position in the entry hole in a relaxed or unsealed state before the adjustment step that completely compresses the grommet, and wherein the grommet assembly is locked by a profiled outer edge of one of the pressure plates that is keyed to a cooperating profiled interior surface of the entry hole of the enclosure base. at a site exterior to the enclosure, providing a compression grommet assembly which includes a compressible grommet disposed between an upper pressure plate and a lower pressure plate, at least one passageway extending in alignment through the upper pressure plate, the grommet, and the lower pressure plate; and an adjustable connector assembly adapted to apply pressure to the grommet to compress the grommet depthwise between the upper and lower pressure plates (26, 28), when adjusted; passing the cable through the passageway in the grommet assembly from a position exterior to the enclosure; positioning the grommet assembly in the entry hole contained in the enclosure base, from a position exterior to the enclosure base, and passing the cable into the enclosure; locking the grommet assembly in the entry hole, from a position exterior to the enclosure; and adjusting the adjustable connector assembly to compress the grommet in the entry hole so that the compressed grommet applies a holding force to seal the grommet in the entry hole and, at the same time, to seal the cable in the passageway through the grommet, characterized in that the grommet assembly is loosely fitted into the entry hole when positioned therein and subsequently moved to a locked position in the entry hole in a relaxed or unsealed state before the adjustment step that completely compresses the grommet, and wherein the grommet assembly is locked by a profiled outer edge of one of the pressure plates that is keyed to a cooperating profiled interior surface of the entry hole of the enclosure base.