why not slip a clutch slave boot over it as kind of a hood? I know the big end would be too big, but might work???
I imagine the push rod end would fit tightly on the eyelet of the cable.
I guess you could get really bored and drill a hole in an appropriate sized freeze plug that fit tightly in the clutch slave boot big end, and then slide it over the cable from the drum end, to work like a shouldered washer?