This jigger mold shell has a step that provides the ideal place to split it into two pieces for printing. It is not necessary to do it in your 3D design app, 3D slicer software has the ability to do just before printing. In Simplify3D you just push the object downward on the platform (anything below does not print). Prusa Slicer (and Slic3r) offer a cutting plane to cut an object in two (after printing the first piece you just undo to restore the removed half and then delete the first section and print the second). Then, after printing, just glue the two pieces together.
Standard 3D printers (not clay 3D printers) are incredibly useful in ceramic production and design, bringing difficult processes within reach of potters and hobbyists.