Here you see magician Steven Bridges doing "Detach" by Rick Lax. (He does it well btw)
The problem is shown in the comment section of the video:
Jahhshhdhdhdj wrote: "Not an illusion. Simply a gimmick piece concealed by the hands"
sam smolyar wrote: "fake"
kostasdeath1 wrote: "lol After Effects ? :D"
And Steven Bridges defends his point by answering to those comments.
So here is the problem. The trick itself might be a cool, impromptu little thing. But the mere thought of an extra piece would destroy the illusion. And you cannot really fight the thought. Sure you can have them select a balloon in the beginning. You could have them sign the opening and the balloon itself. But suddenly we are venturing into a realm of necessary overkill in order to accomplish this illusion.
That makes it a bad trick. The same way the linking rings is a bad trick. The thought of "oh probably a gap" would explain ALL. That is why handing out the linked rings is so important.
With this you cannot hand out the balloon in it's magically altered state. And that is the downfall of the trick.
So to be a little more constructive here is the following:
1. Is the prop you are using free of the suspicion of duplicates? (like any borrowed object)
2. Can the altered state be handed out for examination?
3. Is there no "simple" explanation possible?
If just one of these points is true you have something to work with. If two of the points are true you have a gem. And if all of the points are true you have a freaking miracle.