Cheap 4” filter cup alternative???

[popalud]

While setting up my UNS R75, I saw something and had a thought. Has anyone tried this filled with polyfill (holes needed obviously). They fit almost perfect with the splash guard in place.

 

[Dread Pirate Dave]

While setting up my UNS R75, I saw something and had a thought. Has anyone tried this filled with polyfill (holes needed obviously). They fit almost perfect with the splash guard in place.

Maybe something like this?
https://www.saltwateraquarium.com/4-nosok-filter-sock-no-sock-replacement-silencer-cup-vca/

 

[popalud]

Those exist for sure and likely work better, but I might give the $0.04 option a try. Lol