I looked at your video, to me at least it seems odd that Beneteau would drill so many holes like that at the waterline. What's the point of the holes, I don't see any screws or bolts in them? Might be that you just need to remove the rub-rail thing, thoroughly clean out all the holes, and re-install with new sealant.
1980 S2 9.2A (30') in Anacortes, WA
Aux power 13hp Volvo MD7A