How do I cheat the Pachinko Machine in Super Mario Sunshine?
Looks pretty straight forward and I don't see any major glitches being used here.
There are other videos here and here that complete the pachinko machine in under 30 seconds.
You start by going up the bounce (3 coins)
Land top middle (4th coin)
Jump to mid-top right (5th coin)
Fall directly below the 5th coin to bottom right (6th coin)
Water jet directly left (7th coin)
Go in the back to the start and drop top left (8th coin)
The video that you have linked does not glitch the game, the player simply water jets from the back of the board because it's connected.