QUOTE
My D refuses to turn, and then when it finally does, it slips. Which should I use?
This may sound like I'm sitting on the fence for this answer, but a bit of both might help. I think a lot depends on the fit of the pegs in the holes. A tight fit on one side and loose on the other could create the double problem of sticking and then slipping. Maybe a luthier could advise?
QUOTE
but the Hidersine paste (which I've only used for the first time recently when we had a peg paste crisis) seems to work fine as a lubricant too
Interesting

. I always find the Hidersine makes the pegs hold quite firmly, but without sticking. My experience is that it wears off quite quickly and needs reasonably frequent application.
Eventually, after months (or sometimes years, if you're lucky!) the holes just get too big for the pegs to fit properly and it then means the peg hole needs to be filled, reamed and a new peg fitted.