Pulled the wheels off the R100S so they'd be ready to drop of at Cycleworks for the new Bridgestone install and was pleased to see no excess spline lube had been pushed out and slung around inside the brake drum.
There are occasional posts regarding the importance of greasing both the rear drive and transmission input splines to insure their longevity. There's also the note about not over-greasing the splines.
I imagine that new Airhead owners ask themselves, "Self, how much is too much?"
Here are two photos from the R100S just after I removed the rear wheel. Just the smallest bit of squeeze out indicates the use of the correct amount of spline lube.
I use Honda Moly-60; available in small tubes at any Honda dealer. There are other high-pressure, high-temp moly grease products out there but finding them in small quantities is often difficult. Having to buy a one-pound tub is several lifetimes too much plus kinda expensive.

The brake drum and interior is bone dry. I have seen Airheads with no grease and with way too much. Both can lead to problems. Honda Moly-go is a grey color. You can see just a smidgen on the outer edge of the spline cup.

Just one small hanging 'booger' of moly grease drawn out at disassembly. I recall one Airhead brake shoe assembly that had the springs and metal brake shoe bits covered in grease. No wonder the owner couldn't get a good rear brake while riding!