Kunststoff makes perspex cleaner but I am definitely curious what anyone else has to say. Never used it, I only know that they make a few cleaning products for plastics....
I'd be hesitant to try any chemical or solution unless it had specifically been tested on microphone surfaces.Most acrylic is used in applications where transparency (not insulation resistance) is the most important attribute.The last thing we'd want is any kind of residue that would leave us worse-off than when we started!
Most specific glass / plastic cleaners that head for a visually cleaning contain antistatic components.This is the opposite of what we want!
For acrylic I’d suggest deionized water with a bit of pure Isopropanol (to solve grease).The Isopropanol does not harm, according to https://www.thyssenkrupp-plastics.de/de/acrylglas-richtig-reinigen
For heavier dirt, especially greasy dirt, you can use a plastic intensive cleaner. Benzene-free pure petrol (white spirit, light petrol) or isopropanol is also possible.It is important that the cleaning agent does not contain benzene, ethanol, alcohol, organic substances or thinners. These can damage the acrylic glass.
Isopropanol is explicitly mentioned as usable for acrylics.You don’t need much, 10% is enough (the exact value doesn’t matter) to eliminate water’s surface tension an solve greasy contaminations.In my experience the whole process isn’t critical at all.Once washed, any conductivity is gone.Tip: don’t dry-wipe, or you will bring back contamination.If necessary I use a water-capable vacuum cleaner to suck the fluid away.Of course, don’t vacuum close to a mounted capsule.
One more question—if isopropanol is safe for acrylic, would there be any disadvantage to using 99.9% pure anhydrous isopropanol?
