Chain drive vs belt drive

The correct one is the white lithium grease, comes in a spray can. But it always come out to fast to do a good job on the chain. You only need a light coating, or else you'll coat a whole bunch of stuff with it. I like a 50/50 blend of straight 30w and full synthetic 2t oil in an oil pumper.
How often?
Dupont chain wax or Triflow are my gotos. Both incorporate teflon/ptfe. Triflow even works well on o-ring chain... Not that we use that type chain on our mb's - too much drag from the o-rings. I used to use PJ-1on my motorcycles , back in the day. Then tried triflow and discovered it almost eliminated stretching. A powerful indication that bushing/pin wear were greatly reduced compared to PJ-1.