Creative! I'm srprised I hadn't thought of it before. Will you also try and capture the Cthulhu body part bosses into a build of him? Cause that could be quite the sight
Tip for catching - the Dutchman spawns off-screen, to the right or left. See the wiki for reference so that you may build your entire build first and then attempt a couple invasions to spawn the Dutchman in the bottle.
And as for the bottle - lengthen the bottle, curve the edges a bit, add the tiny wood support diagonal beams to the wood support beams under it, try sloping the wooden base, add the cork.