How do you hold down the button to reverse the funnel?

it is poo

You might want to also improve the design. The map is huge, and it could use a big reduction.

Well there is some issues to fix :
- Getting stuck on the second bridge as said Liliana of the Veil
- Getting stuck in the funnel if you are tracted in it (under the first platform)

For the rest the puzzle was cool and not too hard ;)

This is a great test chamber, one which I have not found a solution to yet. However, if you get to the farthest bridge, you will be stuck in that area - able to only die in the pit and respawn (which can be fixed with a faith plate)