My desk area at work gets very dusty, and bleach is used for cleaning, so it can be a bit corrosive. My current computer speakers are on their last leg. It takes a lot of fiddling to turn the volume up without static or just cutting out. I have a set at home I could bring in, but am not sure I want to donate them permanently, and if they’re not covered, that’s what’s going to happen. Will it be harmful at all to cover them with plastic bags? Could it cause overheating or anything without the free airflow? It’s a smallish subwoofer with a pair of little towers on stands. I was thinking of using plastic produce bags or something. Cloth covers might be okay, but I was thinking the plastic might be better protection from corrosion.
If your work environment is dusty and corrosive I’d worry more about the computer than the speakers. The problem you’re having with the scratchy volume adjustment isn’t uncommon.
If the satellite speakers don’t have a power source and don’t get warm when running they should be fine to cover. The subwoofer probably shouldn’t be covered due to heat.