There could only ever be a refinement of Klipahs Nogah as a result of performing Mitzvos whilst utilizing permissible items. Whereas regarding the three Klipohs of impurity, through abstaining from transgressing a negative prohibition, will only affect a 'shove' - pushing the impurities away.
Logical Understanding and Attainment
Even though the Nisyonos (Trials and Tribulations) descend in a disguised manner, being that they conceal the vitality from HaShem and his holiness blessed be He, the vitality from HaShem is concealed therein, only that it has fallen and descended low in levels of concealment. But when a person stands in a 'Nisoyon' and strengthens himself in the face of any obstacle, then all the masks and covers that are concealing and hiding the Divine light and vitality from HaShem are torn away, and the Divine light and vitality from HaShem comes out from the concealed to the revealed and the revelation continues into his soul to extend to it a state of knowledge and Divine revelation of His G-dliness blessed be He...and as a result of the ‘Nisoyon’ a refinement takes place and out comes the good which is hidden that fell from the supernal previous world of 'Tohu' which fell below into that which conceals it which is from where this ‘Nisoyon’ comes .... and this is so if there was a refinement of the three Klipos of impurity which are spiritually lower than Nogah.
Understanding and attainment: Which is an Avodah within the confines of measures and boundaries, as much as the intellect and grasp of that individual can attain.
