Please make sure that your soaps are no larger than these dimensions:
Small: 1-7/8 x 3 x 7/8 inches
Medium: 1-7/8 x 3-3/8 x 7/8 inches
Large: 2-1/2 x 3-5/8 x 1-1/4 inches
You might try cutting your soaps to these sizes and allowing the shrinkage to take care of a perfect fit.
Remember, all boxes have windows to show off color and odor. To make your soaps stronger in scenting, spray the inside of each soap box with your choice of scenting oil and then close up. The box will retain some of the scent and give it to the air as well as back to the soap.