What do you use to keep high gloss speakers clean?

I also use the Meguiars on the Wilsons. What really works well on the Camaro is Bead Maker. Easy on spray gives a brilliant shine on paint, decals, and windows (ala Rainx). I'm sure it would work wonders on the Wilsons. But I'm not driving them the same. Well, sometimes.😏

Just took my Wilson’s to the detail shop. Got them waxing my bowling balls too.

Waxing one’s balls, whatever next…

Bowling balls you smut merchant LOL 

The Meguirars is quite good.  Pledge, which I also use on my racing car, is easiest.  Pure carnuba airplane wax if your speakers are exposed to UV light from a window.  Zaino wax gives the deepest breathtaking 3D liquid-like gloss I have ever seen, but takes a great deal of time to apply to a vehicle.  It might be worth it for furniture having a smaller size as you mention.