Start by just playing a single note of the melody, like an outline of the whole thing. When you do that, the triplet is of course not included. These professional pianists have such a clear idea of what they want to show, that even when they play the triplet, the melody line doesn't get disturbed. That is the challenge that Chopin put in these measures. To play the triplet without mixing it into the melody.
When you get a clear idea of the melody, try the following motion (I am looking forward to reading your feedback of this):
Imagine a clock facing you, hovering in front of the keyboard. So at 3 o'clock and 9 o'clock create a line parallel to the keyboard. 12 is above the keyboard and 6 at level with the keys. Your wrist begins at 3 with the first octave. There, it goes down until 6 o'clock and you play the triplet. When your wrist goes up to play the last octave, it reaches 9 o'clock. You drow a small arch with the wrist, starting above and on the right side, dipping into the middle and rising from left.
Now, the best way to talk about it is to sit at the piano and play together, but this is more or less how I felt when I was working on that section. Do you find it helpful?