I liked @JohanRosen_1060011 Big Poop Chute, but wanted to make a few changes to it.

I changed up the hole size to use the 8x3mm magnets I had on hand, I also didn't like the added space the handle took up so I removed that. I find a lot of smaller plastic bits behind my printer and was worried he holes in the side of the container would be an issue so I removed those.

In hind-sight I think a lighter color would make it easier to see how full the container is, also might put the holes back in the sides to make is easier to see in.

I only used 6 magnets on the container and that seems to hold just right with 8x3mm magnets.

Magnets I have on hand were a press-fit and go in just a hair under the surface of the print. I didn't use any glue but you might need a dab to keep the magnets held in.