When I looked into getting the various sealants for building my engine, I ran
across the BusBoys site and their listing of Elring-Curil Products.  I
thought that getting the sealant from the company that made the gaskets would
be the best idea and it is what VW did.  

The K-2 is the same stuff from the factory (It smells like and looks just
like it) and the T is what they made for sealing the rubber head gaskets that
they sell to VW.

I have used various forms of sealants on my VW's over the last 18 years and
the Curil products have worked for me better than the rest so far.

While others have their opinions, I chose to get the sealant made for and
made by the company that makes the rubber head gaskets, plus they cost than
VWs prices.