I guess the pruning and the drying out are the most often used methods of inducing dormancy for some plants that don't tend to go dormant on their own without either a period of cold weather with even perhaps a frost killing the top growth, and usually it's a matter of storing them at cool temerpatures with barely enough moisture to keep the roots from drying out too much through the dormancy period. Some passifloras will go dormant in some zones or get nipped back to the ground and stay in the ground til spring rolls around again, provided it's a zone , that doesn't have the ground freeze to any depth through the winter, and usually where that cool ground isnt soggy all winter. Cool basements , unheated sunrooms and garages are the most often used locations. Here an unheated garage might get way below zero in some cases , so I'd not use a garage here for storing plants that won't take freezing.