I have a 2007 GPS Bubinga Warwick and I finally ran my first pot down, so bought a refresh.
These days, the wood on the body and neck (Ovangkol) on my Warwick is pretty much saturated with with beeswax, but I like to do it each time I change the strings just to bring the finish up and give me the comfort that I am cleaning and protecting again.
I would recommend applying with your fingers for two reasons - firstly, the warmth of your fingers really helps with the penetration of the beeswax and, in my opinion, it brings out a better finish and really allows the grain to 'pop'. Secondly, it allows you to be more accurate with your application. It is easy to over-apply it with a cloth and get it in all over your hardware, which looks messy and is hard to remove. Going back to what I said above, it is best to do this when the strings are off.
I leave it on for a couple of minutes and then buff off with a clean cotton rag and it results in the guitar looking fantastic. Don't leave it on too long as it is harder to remove and get an even looking finish.
It can also be used for cleaning. Go to the Warwick care website for information on how to do this, there's loads of really useful information on there.
Finally, just be aware that the wax makes your fingers feel a little 'grippy' when you've just applied it, so fast finger funk is harder to play just after application! Go and wash your hands and dry them out, THEN play!