I/O chain help

I want to set up an I/O chain on my TTT map for a easter egg knife and i want to make it so only the person who figures out the puzzle can enter the secret room. Is there a way of doing this, because currently after its solved it turns into a free for all to get it.

Once the puzzle is solved enable a trigger multiple where the winner is standing.

targetname winner

Now you can use a trigger push or whatever else you want, with filters, to filter through ‘winner’. Everyone else would get pushed back by the trigger push

anyway you can elaborate more on this?