If you start up the Puck holding BTN1 down then it shouldn't run any code whatsoever and will also clear out any saved pairings. At that point you should be able to connect and run require("Storage").eraseAll() to completely clear everything out and return it to a 'factory fresh' state
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
If you start up the Puck holding BTN1 down then it shouldn't run any code whatsoever and will also clear out any saved pairings. At that point you should be able to connect and run
require("Storage").eraseAll()
to completely clear everything out and return it to a 'factory fresh' state