Depends on the hair texture, and the look you're going for.

Lorraine Massey says curly hair should be cut dry only. The Ouidad carve and slice cuts and the Torch tunnel cuts are done dry, too,

Lorraine Massey's reason is so that you can cut each individual clump and the bottom of its curve to enhance the curling ability, instead of just chopping it off mid curl which promotes the ends to frizz out.
3b (with 3c tendencies) on modified CG