Found this website:
"Using a petroleum based grease can dissolve polyurethane products"
Snake oil or should I give it a shot with my squeaky polyurethane?
Now these people say something different
"Parker O-Lube is a petroleum-based grease
recommended for use with polyacrylate, Vamac, neoprene, fluorosilicone, nitrile, HNBR, polyurethane
, fluorocarbon, Aflas, Hifluor, and Parofluor o-ring materials"
OK, I'm lost - so Will is ANY lube ok or what?