Theaudiotweak, no musical instrument I know of has ever been influenced by something I can stick in my pocket. Acoustic grounding of a string instrument through tail pieces, end pins, chin rests of differing designs and materials is another kettle of fish all together. Even modifying instrument resonance by the application internal/external of any material, or altering the composition / shape / etc. . . of any component will alter the sound. . . but putting a 'lucky charm' in your pocket will not be noticeably helpful, even with cryo-treated batteries, that would be dead by definition.