1. Find berry bush (I've only tried the red ones myself)
2. Press "f"
3. Wait for the last moments of the berry picking animation
4. Spam "f" wildly just as the animation is about to stop

Pressing "f" too early in the animation, even once, will make the exploit fail, at least according to my own experience. If your timing is good, you might get more than 1 search message. Not sure if the timing is really specific or if the exploit doesn't work every time.