Another reason would be the damage that has been done to the two biggest body cleansing organs (the liver and kidneys). If these are ridden with alcohol and have damage to them, the body has no other way to elimate the toxins/waste but through the pores. Thus the disgusting body odor. The other reason is that some alcoholics/addicts tend to not engage in the most pristine hygiene and the body odor can be as a result from poor grooming/hygiene or lack of.