The best audio tweak is a soft bristled paint brush...

Oh, I should mention, I do not use a water dampened washcloth on paper/pulp speaker drivers. Just on the speaker cabinet and on poly driver cones as well as electronic component exteriors. 

I keep a couple of natural bristle brushes in my toolbox for such purposes.

Once every few years I'll give my amplifier circuit board a good dusting with a gentle brush.

My PC on the other hand, seems to need it once or twice a year.

In particular, the CPU fan/heatsink.

For those fragile lacquer and wood finishes microfibre cloths are a safe choice.