All illusion comes and goes, but the soul remains unchanged. What is meant by God-realization is to actually experience this important thing that the soul is eternal.
The best way to cleanse the heart and prepare for the stilling of the mind is to lead a normal, worldly life. Living in the midst of your day-to-day duties, responsibilities, likes, dislikes, etc., will help you. All these become the very means for the purification of your heart.
The experiences which drugs induce are as far removed from Reality as is a mirage, from water. No matter how much you pursue the mirage, you will never quench your thirst, and the search for Truth through drugs must end in disillusionment.
