Qlippoth are rather difficult idea to grasp. Their name in translation means husks or shells. Qlippoth are directly related with the Kabbalistic idea of creation. It is believed that initially we all were part of a big vessel and all souls were related to one another along with the Creator.The souls and the vessel received all they needed from their creator, but they could not give anything back to return the favour. As the time progressed, within the souls so called "Bread of shame" arose. Souls felt very guilty for receiving everything for free and not giving something in return, so the more guilty they felt the more they started to turn away from their creator. As they kept pulling away the vessel expanded even further. The Creator realized that the souls want to earn their privileges and decided to further give them freedom to express their Free Will. Now, you got to remember that souls do not have that many needs to really have to do something or give up on something to earn anything. That is why they had to become more denser and more needy. This caused the vessel to shatter and separation occurred between the World of Ein Sof and the lower levels of existence, which souls and incarnated souls inhabit. The Tree of Knowledge started playing the role of communication and transport system between all levels. After that, the connection between souls and the Creator was not direct, but had to go through all Sephirot because the souls now have fallen into much more dense and material levels. However, when the vessel shattered pieces of it caught the divine sparks into themselves , so they themselves were creations of the Creator, but the forces of so called "Other Side" infused their energy in the shards. Those shards are called also husks or shells because they are outer dark husks that have trapped a light sparks. Instantly, the role of the husks became the one to challenge the light within the souls, so they can earn the light of their Creator. Therefore, they are viewed as metaphysical shells of negativity, despite that they contain sparks of light. That is what initially the souls wanted to earn the light they were given for free. The light I am talking about in this case is the very essence of their soul and the energy than maintains it.
According to my teacher and the Lurian Kabbalah, when a unborn child is inside his/her mother's womb and is all surrounded by water the shells and the negative forces infused in them cannot get hold on the child because the water surrounds it. Water is perceived as the element related to the merciful aspect of the Creator, which is very feminine in nature. However, even if a tiny strand of hair sticks out of the water the shells will be allowed to get hold on you, as long as you do not restrict all your negative emotions and thoughts on all levels of existence.
Restriction in way is earning the light because you sacrifice something in return of something and you have to use all your will, discipline and work hard to not give them leverage.
The souls of the dead also need to do restriction, but theirs is different in nature and much more easier than when you are incarnated soul. Qlippoth are very hard to deal with and remove for long periods of time, they have very clever ways to protect themselves. They will always be negative and will keep you in negative state of being until either you do not break our own outer husk or darkness or break theirs to release the light spark they trapped, which now serves as their energy source.
There are three ways to deal with them.
Immerse yourself all way through water and stay there as much as you can. In way this is a sort of a cleansing. Of course, once you are out of the water and do not restrict and control every single one of your aspects on all levels, they will return.
Starve them by not giving them any energy and attention. This sounds much more easy that it actually is. This requires extreme levels of patience, focus, knowledge and control. It is believed that only sages are able to achieve this state of being and achieve such self-control. The rest of us can manage on average with average success. For incarnated souls this is much more difficult than for the ones that exist in more subtle planes of existence.
Feed them so much light that it breaks the other darkness husk and releases the light spark within them. In this case they cease to exist as shells and their energy is transformed into pure light and returned to its Creator. This also on itself is an extraordinary thing to do.In order to be able to do it you must have restricted and earned so much light and have elevated your soul to the upper levels of Tree of Knowledge to can tap into and channel directly the energy of the Light.
Keep in mind that the different types of Kabbalah have slightly different versions of this information. Hermetic Kabbalah appoints a secondary Tree of Knowledge, which is shadow twin of the light version of it. The Sephirot on this Dark Tree of Knowledge are also called Qlippoth. It is believed that each of the Sephirot on this tree is related to the different types of negative energies that came from the "Other Side" and attached themselves to the shards as the shattered vessel.
If a soul deliberately chose to work with the shells this soul will gain different type of knowledge than the ones that decided to restrict and cling to its light twin. This knowledge comes at a price through. When a soul has not earned the light in this life it has to earn it in the next at the same time the more knowledge you have the harder you will be tasted to earn what you wanted to earn before the vessel shattered. A soul has to do what it has to do does not matter if it takes it 100 years or one million years. Of course, if you wait that much and have gathered that much power and knowledge your challenges will be matched accordingly.
It is good that you have asked this question. I have been planning anyway to do a thread in the topic.