Graphite works best I find Graham, it's just a bit messy. I use it on my newer rods as a thin coat is all that's needed.
I use candle wax on my older rods, as I find it takes up a bit of the slack in the joints, making a better fit which is still easy to take apart.
Graphite is easier to clean off the joints as well - wax is sometimes a bit of a bugger to remove.