What about getting a thick piece of filter mesh that you can cut to size to fit in the holder and cut a glory hole in the middle of it for your pipe? Something like this:
www.marinedepot.com
Any splashing would be contained by the mesh, but the mesh would still allow air flow through the sock so your system won't pressurize and can still safely overflow if the sock clogs up.

Aquamesh Black 1 - Extra Coarse - Lifegard
Progressive density mesh mechanical filtration system can be used as a system or separately. Aquamesh #1 is great for removal of large debris and free floating particles most commonly used as a first stage to allow longer use of finer stages between cleanings. Dimensions:19.5" x 24" x 1.5"...

Any splashing would be contained by the mesh, but the mesh would still allow air flow through the sock so your system won't pressurize and can still safely overflow if the sock clogs up.