I have read about King & TKHP pre-filled connectors, but why not use regular wire nuts & vaseline, or perhaps the in-line splice types (squeeze shut), also filled with vaseline? Or if not vaseline, then a high-temp grease? From King's website: King Innovation Tan Low Voltage (30v, 10 amps max) wire connector contains petroleum based sealant, replacing electrical tape, heat shrink, multi-piece waterproofing, and direct bury kits on many low voltage underground applications. Which makes me think that petroleum products won't harm the insulation. My only concern would be the vaseline (or dielectric grease) melting and dropping out... Just some ideas that have wnadered thru my head today.