How can I make a DIY cleaning solution for shower door scum?

Here is a great solution! Don't forget to follow up with some RainX to keep it sparking clean! https://www.hometalk.com/diy/clean/bathroom/3-ingredient-green-diy-soap-scum-remover-for-your-glass-shower-doors-21433429

3 Ingredient Green DIY Soap Scum Remover for Your Glass Shower Doors

Here's my favorite. It works great on shower doors!

https://www.hometalk.com/diy/clean/bathroom/diy-3-ingredient-tub-and-tile-cleaner-18973805

Plain old white vinegar . . .

Here's a great article https://www.hunker.com/13421533/best-way-to-clean-soap-scum-off-shower-doors

A mix of 1/2 rubbing alcohol and 1/2 water spray and let sit for a few minutes. Then it should wash it off

No more scum

50/50 white cleaning vinegar and blue Dawn.

I use a 6 part water 3 parts vinegar and 1 part soap and spray it on, let it sit and then wipe with a wet rag before rinsing.

Here's a post that might help https://chascrazycreations.com/clean-bathroom-natural-products/