I've seen some DeviantArt pics that try this method. While I figure the duct tape sheet wouldn't be that conforming in real life, rolling would stick the extra space together. But yeah, I'd have to agree that since you're layering ducttape to ensure a sheet, you're already dealing with the difficulty of escaping via seams.
...Speaking of duct tape, I also saw some DA pics of duct tape people. That is, after wrapping yourself with plastic, you then wrap each limb in colored duct tape, at least a beige tone for the body and other colors for socks, shorts and shirts. Hm, I wonder if one could also add a mermaid tail to that as well.