According to this,
http://en.wikipedia.org/wiki/Madison_(name)
Madison as a given name has never been all that popular but was used as a given name for boys well before the 1984 movie Splash. Some examples are:
Madison Smartt Bell (1957/), novelist
Madison Cawein (1865/1914), poet
Madison Cooper (1894/1956), American businessman
Madison Jones (1925/), author
Madison S. Perry (1814/1865), fourth governor of Florida
And it was also used as a middle name, most often paired with James.
James Madison Carpenter (1888/1983), Methodist minister, scholar
James Madison DeWolf (1843/1876), surgeon
James Madison Wells (1808/1899), governor of Louisiana
Clarence Madison Dally (1865/1904), American glassblower
George Madison Adams (1837/1920), U.S. representative from Kentucky
As far as Madison as a girls name, yes that didnt seem to become a popular name for girls until the 1984 movie Splash which was a modern retelling of the Hans Christian Andersen fairytale The Little Mermaid. I havent seen that movie for years but I dont recall the character Madison as being particularly slutty. OK, she did come out of the ocean and walk around naked but thats because she was a mermaid and rather innocent and naïve and evidently living under the sea as a mermaid, clothing was optional. Then there is the Disney movie version of The Little Mermaid but unlike Madison, Ariel isnt naked but wears strategically placed sea shells. :) ,
The sluttyness has nothing to do with nudity. The character in the movie meets the guy for a few seconds and then follows him for sex at his apartment.
The Little Mermaid cartoon character doesn’t behave anything like this.