Abstract: The present invention addresses provides a clean-out plug that seals a pipe system clean-out that includes a clean-out end and an inner surface, a portion of which is threaded. In general, the clean-out plug includes a compressible sealing member that is retained by the clean-out plug and that seals against an inner surface of the clean-out and/or the back side of the threaded portion of the clean-out. The clean-out plug may also include a cover plate that is secured to the clean-out plug via a second retaining member that engages a first retaining member of the clean-out plug. By sealing against the inner surface and/or back side of the threaded portion of the clean-out, various embodiments of the present invention do not seal within the treaded portion of the clean-out, which is often damaged by cross-threading from previous removals and reinsertions of threaded clean-out plugs.