There are so many chain lubes out there and they all claim to be the holy grail of lubrication. Pick your poison,its just chain lube.
The dealership will tell you whatever you are using is
cr@p and you need to buy their wonder product or you bike will immediately explode(it probably wont)

I use this and it works great,cheap too:
http://www.webbikeworld.com/t2/motorcycle-chain-lube/dupont-teflon-chain-lube.htm