As with spells, i believe that the hp check on that is server side, thus no bypass. What I have seen people do is get dotted while in guild hall (their own dots), (or warlords tenacity for warriors) and get the hp drain just right so they can keep bindwound. i imagine you could /duel for dots as well, or have a pet hitting you for semi constant damage amounts. could do a script to back it out if you get below x %.