I changed the manual gearbox oil at around 65 k on ours, used about 1.3 litres of Honda oil ( it actually says on the bottle "For ALL Honda manual gearboxes") and couldn't really see a difference between the oil that came out and the new oil that went in ... both were clean and golden, with no swarf on the sump plug magnet.
It obviously does it's job well, because at 132k miles, the gearbox is as slick now as it was at 20k miles.