A simple indicator to show if the contents of the dishwasher are clean or dirty.

I got some magnetic backing that attaches with double sided tape to the back of the print which allowed me to stick it easily to the dishwasher.

The endcaps are optional.

You may want to adjust the tolerances to get a good fit, or alternatively, take a sharp knife to the slider and take it off piece by piece to get a nice sliding feel.