This technique is called exposure therapy. not all those who have depersonalization like you do can do exposure therapy.

what treatment providers do around here is called "grounding". this is a therapy approach where those with dissociation problems are taught how to pay attention to their feelings. then when they feel their symptoms coming on us "grounding". Grounding is utilizing anything that is calming to you that will put you back in touch with yourself and your surroundings.

some people use strong calming aroma's others use looking around the room and naming what they see, others count, still others use focusing on textured things... the list is endless of what a person can use to help "ground" their self back out of dissociation.

one of my favorite things in grounding is the aroma and texture of apples and cinnamon.

if I remember right there is also a thread on grounding on these boards, and there is a chat group that meets here on psych central about grounding. I dont remember what time and all the details but Im sure someone else here will be able to post that info for you.