There were several theads on this, some for the 650 but its the same on the 1100 - they dont show up on searches, so maybe some of the pages got lost in the last forum glitch.
Read this webpage: 650 CC & D
I got Loctite LB 8012, part number 51048. Its about $30 for an 8oz bottle on amazon.
Yes its expensive. Yes 8 ounces will last you for every motorcycle you own for the rest of your life.
Its referred to as moly paste and anti-seize compound. It has the correct >60% moly formula.
I did not pull the splines apart until my bike hit 35,000 miles on the odo. There is nothing in the 650 owners or service manual that say lubing the splines is a periodic maintenance requirement (like lubing your clutch cable, greasing the steering head and swing axle bearings... that stuff is called out as required, the shaft splines are not.
when I pulled mine apart at 35k miles they looked like new - so whatever was put on them at the factory was doing its stuff. I wiped them all down and used the Loctite 8012.
The biggest thing you have to worry about is taking your bike to a local shop to get the back tire changed. If they wipe the spline moly grease off and put some axle grease on, it will not last 100,000 mile. It may not last 20,000 miles. If you think $30 is expensive, google what it will cost you to replace your splines if the grease runs dry.
If you have ever owned a chain drive motorcycle you know what a pain it can be to keep the chain lubed, and even if you do the rear sprocket wears out anyway, and you will be buying new chains and sprockets over the life of the bike.
The shaft drive is intended to be maintenance free for the life of the bike. Most people pull the splines apart when they change the rear tire, or maybe every other rear tire. Compared to lubing a chain every 500 miles, its a big improvement.