There are two major types of wax on the market ... hard wax and soft wax. Each will lube the zipper just fine. Each has advantages and disadvantages.
Soft wax can be beeswax or something like ZipTech. Advantage is that it doesn't wash off the zipper during the dive (you don't have to wax for every dive). Disadvantages are that it tends to collect dirt and grit, and every once in a while you'll have to take a toothbrush to your zipper to remove the buildup. Soft wax tends to provide a better lubricant, but unless you use proper care the grit that sticks to the residual wax can put more wear and tear on your zipper (and zippers can run upwards of $400 to replace). For general applications, consider that if you're mostly boat diving, where the environment is reasonably grit-free, this is a good choice. If you're diving from a beach, probably a hard wax would be a better option.
Hard wax is like paraffin ... it can be the stuff you buy in the canning department at the grocery store, or something commercial like MaxWax. Advantage is that it doesn't buildup on the zipper like the soft wax, and therefore doesn't attract dirt and grit to the same degree. Disadvantage is that because it washes off rather quickly as you dive, you need to apply more often (every dive, generally). Hard wax tends to be a better choice for shore diving, where dirt and sand getting into the zipper can be a concern.
Someone asked why store the suit with the dryzip open ... it's because dryzips are not built to bend ... and folding a suit for storage bends the zipper. An open zipper is more flexible than a closed one ... and so you're putting less stress on the zipper when you store it with the dryzip open. Closing the outer zipper can be a good idea or a waste of time, depending on how the suit is being stored and transported. A good drysuit bag will protect the suit (and zipper) from dirt anyway, so closing the outer zipper is unnecessary. I like the clamshell-style bags ... like Diving Concepts ... because I shore dive a lot, and the bag can double as a place to stand on while you're changing into and out of your suit/undergarment.
Hope this is helpful ...
... Bob (Grateful Diver)