Thanks for that! I have about a metre of hose to hang for my thicknesser, jointer and drum sander which all share one connection, so a bit of experimentation is needed I think, although it’s not as bad as it sounds as the joint will take most of the weight.
Perhaps I’ll start with no embedding of the magnets and use 8 of them. “Start” in this case probably means if that doesn’t work, I’ll give up! 
Embedding them even 1mm means a 2mm gap. Now it’ll be a race between my LR parts and the magnets as to which gets to me first!