geoffkait you have been around a long time and I can't comment about your products but I have come across others that do use crystals in their power cords. I only know this because of wanting to change their connectors and found them within them.
Brilliant Pebbles, a new tweak, cheaper than high end cables.
"Brilliant Pebbles is a unique and comprehensive system for tuning the room and audio system based on special physical properties of highly symmetrical crystal structures.
Brilliant Pebbles addresses specific resonance control and RFI/EMI absorption problems associated with audio electronics No snake oil here.