An old trick to get rid of a noisy engine was to slap some gearbox oil in SAE 80 or 90, so yes.
Lots will recommend the VX genuine oil £37 at the local stealership 4 or 5ltr can.
Had Castrol Edge 0w/40w in for a week (5w/30w circa recommended) before cam chain change, a lot smoother, quicker to turn engine over, quieter and swear blind it was better in the fuel stakes- can only be a good thing but pricey.
So the Castrols its going back in complete with Molyslip.