choke cables

Three of my hanger queens are afflicted with terminally (?)
stiff/frozen pull cables.  One is the choke on the Bugeye, one the
fresh air cable on the 70 Midget, and all three cables on the TC are
about frozen.  Is there a procedure to resurrect these puppies to some
usefulness?  Like remove and soak in a bucket of oil for a day or clip
the dog legs off the end and remove the internal wire, sand and try to
reinsert?  Anyone BTDT?   Thanks, Larry.