From the book "To Ride A Silver Broomstick" by Silver RavenWolf
While you are working with the chakra centers you may discover that some seem to shine brighter than others on different days, or that some may have dark spots in them from time to time.
If this happens, it means that you are aware that there is an imbalance in one of the chakras. Don't get excited; they just need to be fine-tuned a little.
While doing the meditation exercise, work extra hard on the weak vortex. This can be accomplished by raising the vibrational level, or adding white light from the Universe to bring it into balance.
Another method is to make a black spot vacuum ball. Visualize a swirling ball at your feet. This ball is designed to suck up negative energy like a giant vacuum. Allow any dark spots on the chakra vortex to be swept down to this ball, where they are absorbed. When the spots are gone, sink the vacuum ball into the ground.
At the onset of physical illness, you should
also use the vacuum ball. Open the chakra center that is closest
to the illness, such as the throat chakra for a sore throat, and
clean it out with the vacuum ball. Once the illness has
physically manifested in your body, it may take several sessions
throughout the day with the vacuum ball to bring the chakra into
balance.