Manguangua means that something is really easy or made without any considerable effort. Often to refer to someone doing something the easy way because they're lazy.
"Quieren hacerunas elecciones con los principales candidatos inhabilitados. Que manguangua vale."
Psycho slut stripper who accused three Duke Lacrosse players of rape and tried to ruin their lives. She was later found to have 5 different men's semen on and in her, but no lacrosse players.