My latest 'project boat' has globs of sealant (unfortunately looks like white silicone) around the bulkhead edges.

Sometimes you've got to laugh when you see things that people have tried. In the picture, I've already removed about 90% of the sealant which was about 1/2" thick in the angle between the bulkhead and the hull.
I hope the pic is clear enough to show where the bulkhead was actually leaking - there was a lot of sand in there when I shoved the putty knife through, so it had been an 'ongoing problem'.