If you feel sick or „dirty“ in your main chakra system (see spirituality page of my blog site), it may not be even in your main chakras but possibly also in your side-chakras, you can conduct the following little chakra cleansing ritual:
You may be sitting, lying or even standing, that is not too important, but you should be in a relaxed state of mind.
Now form a „claw“ with your hand as if you were holding a ball. Preferably start with your base chakra. Move that „claw“ counterclockwise („being the chakra the clock“) in front of the chakra to be cleansed and visualize the „sick“ or „dark“ energy being sucked into that „claw“. If you feel the chakra being cleansed throw that bad energy into the universe and let the universe get the rest of the job done.
Finally, now you should „heal“ or fill your chakras with light. Form a flat hand and move your flat hand clockwise („being the chakra the clock“) in front of the cleansed chakra and visualize light and the to it belonging color according to the rainbow chakra system channeling from your crown chakra through your spine, arm and hand, floating and filling your cleansed chakra.
Possibly repeat that with all main chakras and maybe with all side chakras.
(Smoke a ciggie afterward 😉 )