Remembering how, years before, I would watch my high school gym teacher coat the needle (air) valve with a glycerine solution before reinflating basketballs, I found such a solution to be effective here. In fact, I redid the bushings on a Spitfire some years ago using "Cornhuskers Lotion" -- available in drug stores and having the great advantage of helping soothe your hands after spending hours in the garage replacing suspension bushings. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
Liquid dish detergent probably would also work for bushings.