Alternatives to foil.

Baking Parchment Paper
Bannana Leaves (available in "poor fok" markets) world wide.
Corn Husks (wet)
100 percent linen or cotton sheets (think T-shirt or bedding or table napkins) soaked with water (remove last 90 minutes...if you want a glaze)

In years past I once used .... parchment paper ... with wet burlap .... it was on whole deer hind-quarters....(courtesy of the Fish and Game department) and buried with hot rocks...imu style.

Sincerely,
Gargoyle

Love me tender, Love me sweet, Wrap your lip around my meat....Watch me smile and watch me grin, as the juice rolls down your chin.