Brown boot polish ?
, no .
WD40 , oily residue everywhere, no . ( its diesel without the smell )
Graphite , like WD40 , gets every where , no.
Baby powder , works well but you cant use it for to long as it falls away and needs redoing over and over , no .
I use good old lip balm , 'Chap stick' as its natural bees wax , clear and does not spread everywhere and stays in place , does not hurt optics ( if cleaned off quick , like a finger print ) , neutral on paint and rubber , so use just a little of course .
.
Great stuff , also good for Crayford focusers as a lube .
Brian.