Ok, who will be the brave one...
FabTek Logic Fin Clamp Baseboard Element for 3/4 in. Copper Baseboard Piping 1 ft. Section-FCL-.75CX1FT - The Home Depot
Home Depot sells a fin kit to add to 3/4 inch copper for heating...
I bet you could buy this, and use each half of the clam shell on your oil line without issue. Easy to add, easy to remove...
I would think it would help cooling quite a bit...