Every VK is locked by Sharat Sir after he attunes it with Cosmic Energies. No one can remove or de-attune any VK. Even Sir himself cannot de-attune it. The lock is so strong.
It is unaffected by hot or cold temperature.
Maybe if VK is put in a furnace and if the bangle melts then the energy may be lost.
I know a VK user who met an accident , luckily VK saved him. He was riding a bike and some other vehicle hit his hand so badly that VK lost its original round shape and it twisted to take an irregular oval shape.
Its still working for him….!!