My dishwasher detergent spout broke, so I made this. It slides on top of the box and tucks into the hole where the original spout once lived to minimize stray detergent granules (or whatever you call them).

This fits the 75oz box of Cascade Complete. Maybe it fits other similar products? You can check the dimensions below.

Width: 50mm Depth: 170mm Top of box to bottom of spout hole: ~40mm

The part that hooks into the spout hole is a little fragile (at least in PLA), so be gentle during installation. It needed to be relatively thin to avoid impeding the flow of detergent for a satisfying pouring experience.