My mate does sell a Lucas oil to replace the EP90 in swivel hubs that cuts down the oil leakage, but I don't think it's an extreme pressure oil suitable for diffs, it's formulated for CVs and I use it rather than one-shot.
Unfortuantley the ability to leak is neccessary to make a good lubricant :roll:
I've found Thompson's driveseal ideal for giving my tarmac drive a makeover :lol: