Teflon is almost completely nonreactive: hydrofluoric acid will annoy it but nothing in any cable lube will do anything to it. So feel free to lube teflon lined cables. It may not help, but it won't hurt.
Of course cables advertised as "teflon lined" may be actually lined with something else - or nothing at all.
I generally use motor oil, I usually only notice the clutch is getting stiff on a ride so I pull it out of the lever and dribble some oil down the wire from the dipstick.