3 in 1 SAE 20 is fine but I find it nearly impossible to "drip" a known amount or even reach the fan motor's oil hole inside the power box.
Syringes with blunt tips are legal in all states without an Rx. They can be found at woodworker supply houses that carry furniture restoration materials. Even Amazon has syringes and blunt tip needles. They work great at any angle!
Small medical syringes (not the single use ones) work great for dispensing precise amounts of oil (or glue). Syringes are legal everywhere, it's sharpened needles that are restricted)
Getting a long enough needle (blunt tip to be legal in all states) can be tricky. They can be had in bulk at very low cost per unit at various supply houses.
If one wants bulk (1/20th the price of wood worker kits) Even Amazon carries bulk syringes without needles and blunt tip "dispensing needles" and syringe caps. Amazon doesn't seem to have needle scabbard covers (cover the needle tip), not the syringe) as places such as http://www.howardelectronics.com
have. They are not needed but a little less messy since the needle can be left on the syringe.
Actually, it would be great if Leisure Line tossed a couple oiling syringes, blunt needles and scabbards in with each stove. Bought in bulk, they are CHEAP.