Griff,
If I might offer a suggestion,......
Please describe the location of your oil leak, sharp pictures really help, without making someone watch a shaky video (about made me ill) for several minutes.
This will assure that people read your post and offer constructive & useful solutions to your problem.
I couldn't watch that video, but if you have leaking through-bolt, covering it up with sealant is a poor "repair" and no real solution at all. These have O-rings behind them at each end and if they leak, the only real fix is to pull the engine, remove the heads, and pull one through-bolt at a time to replace the O-rings at each end.
Tightening it simply puts the crankshaft and its bearings into a bind and that has very bad (expensive!) consequences.