Article continues below advertisementShamed Sarah Ferguson's stay at one of the world's most exclusive wellness clinics has sparked questions about how the former Duchess of York managed to fund the ultra-luxury retreat - with insiders telling OK! the visit may have effectively been a free promotional arrangement rather than a private expense.Ferguson, 66, is said to have retreated to the Paracelsus Recovery Clinic in Zurich, Switzerland, shortly after fresh scrutiny erupted over her past relationship with convicted s-- offender Jeffrey Epstein, who died in 2019 at age 66.