A company called Covert Labs makes Strip NC. Its website is a little sparse now, so much of the information comes from other sources.
Looking at the ingredient list on the bottle, we see the usual detox drink components, such as plenty of B-vitamins and creatine. The bottle also prominently declares the use of Psyllerol, a proprietary blend of carbohydrates, vitamins, and psyllium. Psyllium husks are a concentrated source of fiber, so this might help a little.
Under the ingredient list, there's a warning that it contains cascara sagrada and should not be used if you have diarrhea, loose stools, or abdominal pains. Cascara sagrada stimulates bowel movements by drawing water into the bowel. This is fairly unique, but it's not clear how this helps pass a urine test.