In order to start Bottle Adventure, the first thing to do is to get an item that can be duplicated over with a Bottle on B. Getting Deku Sticks on B is the most common first step, since there are several ways to get Deku Sticks on B. From there, we can duplicate a Bottle over the sticks on B, setting us up for Bottle Adventure.
This trick lets you take the Fishing Rod outside of the fishing pond area. It's the easiest, but not the fastest, method for starting RBA as adult link.
By stealing the rod you are able to turn it into a deku stick, which then can be duped into a bottle thus starting Bottle Adventure.
There are currently two known ways that allow us to steal the fishing rod, both use Use Restricted Items and requires either Bomb, Bombchu, or Farore's Wind.
After stealing the rod, do the following:
You will now have Deku Stick on B.
This trick allows you to get Deku Stick on B, using Fairy Remote Control Epona to disable your B button. This method is useless as it requires you to get iron boots. As having either Iron or Hover Boots allows you to steal the rod.
Follow these steps after Disabling your B button with Fairy Remote Control Epona:
You can't equip a sword using the gear menu before performing this, which prevents you from reverting B items back to a Deku Stick by saving or dying.
You will now have Deku Stick on B.
With NewGame Plus you can assign a bottle item to the B button, allowing you to perform Bottle Adventure as Child Link. However, this requires performing Bottle Adventure on another save using one of the other methods above. NewGame Plus prevents you from reverting B items back to a Deku Stick when saving or dying.
The new save file will start with a Bottle on B.
To change the stick into a bottle you must first get rid of all of your Deku Sticks. Now, since putting a bottle on B also activates Reverse Bottle Adventure, it's best if you use a bottle of Bugs, and equip it on the II Button. This will avoid accidentally overwriting important game data. Empty your Bug bottle and re-catch it to have a full bottle on hand. Backflip, then before you land press the Bottle's button and the B button in quick succession. If done right, Link will dump whatever you had out of the newly created B bottle. You can now use the Bottle on B to perform Bottle Adventure or Reverse Bottle Adventure.
You can quickly get a bottle on your B button by duplicating a bottle over your sword. This is the fastest and most flexible method to get a bottle on your B button. However, this glitch can only be done while performing the Death Hole glitch
Drop bugs/fish then pull out the empty bottle Perform the Quick Draw technique using your sword. Hold Z+R and the corresponding C-button your bottle is on, then let go of R to perform a shield swipe. If done correctly, you should have a bottle duplicated over your sword.
After exiting Death Hole by saving and quitting, you will have a stick on the B button which you can dupe a bottle over to RBA outside of Death Hole.
Note
Link does not have to be on his feet immediately after landing on water like on the console version. While in Death Hole, Link will not put away items while in the water.