[SAJ]

Bob. Glycerine is a water-soluble liquid unlike oil, which is hydrophobic or water-hateing.
Soluble oils will mix with glycerine, but I am not sure how well that mix would perform in an Houdaille shock. It is an interesting thought that had never occurred to me.
The ratios of glycerine and soluble oil that will stay mixed might vary with the brand of oil used but the legacy of corrosion that glycerine creates as it sucks up water from the atmosphere would be greatly reduced if not eliminated.
I will try this when I get back to my laboratory from the far North Car Rally I am on.
Soluble oil of any viscosity can be created from the appropriate oil and surfactant combination. So a lubricant much thicker than conventional cutting oil could be made for worn shocks.
SAJ IN NZ