Cleansing or also known as cleaning, purging, purifying, etc is one of the foundations of energy work and should always be done daily, and by everyone.
Think of this, you wouldn’t leave your machines full of dust, dirt, etc, as that would stop it from functioning, the same is with your energy system, so why would you neglect to do it to it?

Cleansing in of itself can be done many ways and in fact you should experiment with it and figure out exactly how cleaning works best for you, as there is literally an infinite amount of possible ways for it to actually work.

The basic methods are rather simple and useful for even advanced energy workers, and should almost always be learned by everyone in the early stages of energy work.
The first method that will be learned almost always is what is known as grounding. Grounding is using your energy to take the taint, stagnation, etc, inside of yourself and forcing it into the ground. This is almost always best to be done with your energy instead of the earth's energy which is common right now in the online energy communities. From others telling me, and my new observations, earth energy and such normally damages you, I didn’t know this because my ES had adapted to it.

Another method that is mostly used throughout your whole energy career, is the cleansing breath method. This is more so visualization and willing to use. Breath in, and then as you breath out will/visualize the taint leaving your body, do this for around 10 or so minutes or until you feel clean.