So I think drawstring bagd are unnecessary to use when it comes to trash bags. You throw them away anyways. But I wanted another comfort solution and stop knotting and doing things to keep the trash bag in place.
Here's what I came up with: the Titebag!
Just put the bag in the can, thread it thorugh the Titebag and tighten it. You can also secure it in a slot of the Titebag.
It's easy to use and remove, keeps the bag in place and all you need is an ordinary trash bag.

Update 26th dec 2021 - V1.1
Thanks to the idea of SteelWeaver at Thingiverse here's an updated Version I would recommend.
The opening goes to the side as he mentioned in his idea and thus the bag pulls itself tighter everytime instead of getting loose.
By mirroring in your slicer you can have the opening on the left or right. I think that goes by preference for left handed and right handed users. :-)

Now try it and I'm happy to hear any suggestions. :-)