Castrol Chain Wax

[Pelikan]

Is Castrol Chain Wax really wax?  When I took my bike to the shop to get some work done, I had a new sprocket and chain put on.  The chain looked as though it had a legit wax on there (white "residue").  Just picked up this Castrol stuff, cleaned and lubed the chain, and at first I thought I didn't put enough on.  Didn't see much of anything on the chain.  But lightly touching a link revealed that there is indeed something on there.

After less than fifty miles, it looks like some sweet gunk and grit is already building up between links/on the cog...

...so is this stuff any good, or should I switch to another brand?  It's gritty and sandy out here.  No rain or wet to speak of.