The other day I went a friends house and found him sitting out back. He was working on his bicycle and found his shift cable was stuck. He took off the cable ran it through a funnel. He taped the tunnel bottom to where the cable exits the sheath. He then mounted the cable and funnel to a verticle portch post and put in penetrating oil to drip through the cable over several hours. It was a neat setup.
Later that day I went to Harbor Freight and found the Cable Oiler below. The cable slips in at the gold part and the oiler screwed to the sheath. The bottom (not shown) is fit with rubber that has a tiny hole for the cable and a fine slit so the cable can get to the hole. The cable and oiler can then be held up and oil put in the top resivoir section. Nice.
Cables on snowblowers frequently get rust frozen. One chute hood adjust cable on an Ariens is $100 and one Snapper cable is $120. Rust freezing is common on both cables.