Personally, I think my dandruff is caused by a history of eczema, shitty New York tap water, and chronic bad juju. After my traumatic episode, I searched the racks of Duane Reade for any type of drugstore-brand scalp treatment, when I came across a familiar face: tea tree oil.
From Midtown or the Village, take the F or D trains that run down Sixth Avenue from Central Park to Washington Square or the N or Q trains that run down Broadway to Canal Street. All four of these trains will take you directly to Coney Island in Brooklyn.
The subway is the best way to go and the fastest. Take the Brooklyn-bound (southbound) N or Q trains (Yellow Line on the subway map) from Times Square to Coney Island-Stillwell Avenue. The fare on the subway is $2.25 one way and the trip take about 45 minutes to an hour each way. Good luck. Native New Yorker.