Clear a MDBT42Q module from all code?

As @fanoush says, require("Storage").eraseAll() will get rid of everything - but if you had stuff in RAM then that will still run, and if it references stuff that was in flash you'll get the Got [ERASED] expected EOF error - a simple reboot will fix it permanently.

The easiest fix for that is actually just to do this to clear the device:

require("Storage").eraseAll();reset()