Graphite additive?

Hi All,
Has anyone ever put a graphite additive into their gearbox? I find that 1st to 2nd gear change requires gentle prompting in my Syncro and my German brother inlaw suggested to use a graphite additive which he has used on several VW`s in Germany with good results? Ive recently done a gearbox oil change and I was blown away by the amount of metal shavings and crap in the magnetic mesh and how much smoother and quieter the gearbox is now. Has anyone used graphite additive in their Syncro gearbox?
Cheers Dave