In your video, your repair seems like it would work, but I'd be afraid that the "other side" of the bailer hole might start leaking, if a trailer ride broke the seam (or some hull banging!! ;-0 ) Would it not be best to just enlarge the hole, glass it up completely and then re-drill the proper sized hole for the bailer? Then you're drilling thru solid glass and not "two layers of glass joined together". Plus you've now effectively glassed the two layers together in a joint. I'd be afraid of just injecting epoxy into a possibly wet and unsanded area and expected to have maximum hold. You're wanting a mechanical "grip" in this repair and clean prepared surfaces would seem to be required.
Or....I guess you could enlarge the hole and smear some thickened epoxy around the rim and then sand/file as needed...as a quickie fix. The first method seems preferred however.
Checking back, I think using sealant is NOT class legal. Since the plastic bailers don't fit perfectly to the curved bottom, some racers wanted to fill and fair the gap left from the sloppy fit. However, that was deemed not allowable. If you don't want it to leak, seams busting apart or not and you could care less about being class legal, sealant is the way to go. I've never installed a thru hull in a boat NOT using sealant (maybe a rubber gasket under the topside nut to help compensate for varying hull thickness) and over the 100's I've installed, they never leak. That said, "LifeCaulk" has about a 15 year lifespan under water, so I've switched to 5200 when using bronze fittings. Plastic fittings I avoid below the waterline...but we're talking about boats left in the water now too. For the plastic Sunfish bailer, 4200, a polyurethane adhesive/sealant, is fine below the waterline and probably preferred. Most silicones, not so.