Three bond or Yamaha bond from a bike shop far superior to normal RTV silicons and for the cork sump gaskets what I use successfully on Jaguar Engines is no sealant but torque the sump bolts and use loctite on the bolts so they maintain correct torque, That never leaks which is rare on Jag engines.
Most oil leaks from cork gaskets are because over time the bolts do not maintain correct torque the heat cycles allow them to back off over time hence the loctite fixes that issue.

On paper gaskets I have also successfully used a coating of Moly grease (CV grease) yes it is messy first time it gets hot but what is does is leave a coating of graphite on the gasket filling any small voids it when removed looks like a dry graphite coating and the gaskets come off with no damage.

First used that on Kawasaki Cam Cover gaskets so they could be reused up to five times before a new one was required, Later Kawasaki Cam cover gaskets came with a Graphite impregnation standard so I was duplicating what the factory did themselves.