In the natal chart, Pluto tends to operate even more Plutonian when it is retrograde. It is far more intense, it possesses a higher degree of concentration and it, therefore, gives greater insights into the subconscious. Because of this intensity, the individual can see much more than normally possible and it is easy to become suspicious of the motives of others.
The powers of regeneration are far greater when retrograde. People with a natal retrograde Pluto have a tremendous ability to overcome major illnesses that might otherwise cause permanent disability. Remember, retrograde motion is always directed toward inner activity such as the psyche or psychological patterns that affect the physical body. Direct motion, on the other hand, is directed towards external circumstances.
Under any Pluto transit, we feel pressured to eliminate and release the old, outworn, outdated and obsolete in our lives. When Pluto is transiting retrograde, we are urged to let go of attitudes, thinking or communication patterns, security drives, rigid emotions; a time to undergo an internal form of house cleaning.
It is a good time to research into our own Souls in order to determine exactly what we do or do not need. Because Pluto retrograde imparts an intense power for investigation, we should use this time to assess what reoccurring patterns in our lives make us feel out of control, where and why do we continually give our power away, and under what circumstances do we react so defensively that we elicit attacks from others. Pluto retrograde marks a time wherein we should seek to gain greater control over our personal life; Pluto direct is better for gaining control over professional and financial areas.
My most frequent observation of Pluto retrograde is that many people do seek some form of regenerative activity. I have seen people undertake a series of internal cleansings, detoxifying diets, Eastern disciplines that put them in touch with the inner self and even intense psychological reforms.
Source = http://www.lynnkoiner.com/astrology-articles/pluto-retrograde