Mix strawberry gelatin with boiling water in a bowl until gelatin has dissolved. Stir in cold water and refrigerate until gelatin is thick but not fully set up, about 15 minutes.
Place about 2 tablespoons of thickened gelatin into the bottom of each juice can. Center a banana half, cut side down, into the center of each juice can and spoon remaining gelatin around the banana, filling the cans up to the top. Chill cans until the gelatin is firm, about 2 hours.
To serve, dip each can up to the rim in hot water to loosen the gelatin; invert cans onto a serving plate and puncture the bottom of the can to allow air in. Lift the cans from the desserts and insert a red licorice string into the center of each dessert to resemble a fuse.