Sly Stone I Still Use Cocaine, Beer ... but I WANT to Get Clean

9/27/2011 6:20 AM PDT

Sly Stone -- ex-frontman of the '70s funk band Sly & the Family Stone -- is admitting he still abuses cocaine and alcohol ... but the 68-year-old singer insists he WANTS to clean himself up.

Stone -- who's currently living in a van in L.A. -- spoke candidly about his substance abuse issues yesterday, insisting he hasn't used drugs or taken a sip of alcohol in "a week and a half."

A discombobulated Stone claims he's chosen a rehab center -- and insists he's serious about it ... saying, "I will be there."