If the negative emotion charged crystal causes a reduction in the measurable field, you know the crystal is holding or storing negative emotions. If the energy measurement increases after the Light Invocation beyond the original measurement, two things are possible. First, the Light Invocation does, indeed, clear out negative emotions. Second, the Light Invocation also increases the overall energy field. Cleansing is a process of reducing the negative emotional energy level of the crystal to the point where the emotional energy can no longer affect you.
Salt is the recommended method.
Cleansing is usually not necessary or even desirable if clearing can be done. The Light Invocation will leave all the energy in the stone. It simply changes those emotions from imbalanced to balanced, from bad to good. This increases the immune system energy reserve by stimulating the thymus gland. Permanent positive energy to enhance business growth, prosperity, relationship peace and harmony.