When a chain is only used for a few weeks throughout a year, you can extend the life of the chain by removing it, cleaning it, and prepping it for storage.
Diesel fuel and kerosene are good options for cleaning roller chain. We would advise you to agitate the chain while it’s submerged in order to remove any debris that might be stuck in an interior joint. Let the chain air dry and place it in a medium to heavy weight oil. This will help protect the chain while in storage and ensure that it’s ready to go for the next year.