Silicon spray is too thin and while it will provide a slippery surface it won't provide much actual lubrication when your body weight is on it.

Lithium grease would be better but use it sparingly in case it bleeds onto your floor. If you open up a tin of that grease and there is a little layer of free oil on top it's probably a bit too sloppy, you'd want a mix with a bit more binder in it. White lithium grease as another poster mentioned would probably be ok.

You used to see "dry lube sticks" around the place which were about the consistency of a tacky/soft wax candle. That's probably what I'd use as it will stay put when you rub it on the tracks.