If there is a DC offset, then a capacitor won't remove the “pops”: there
will be a transient when the DC voltage is applied, and so a corresponding
“pop”. Also, as you mentioned (roughly), the capacitors work as an high
pass filter, that means they will color the audio (or “distort” in layman
terms) and in addition, make everything somewhat less loud.
In other words, following that advice will not remove the pops but it will
degrade the audio quality.
>Nowadays one thing to try is to repeatedly plug 'em in and out to clean up
the dirty contacts.
I don't recommend this unless the jack (female connector) is dirty or very
oxidized or sulfated, as it will also make the connection looser. Otherwise,
use a pencil track eraser or ink eraser to clean the jack instead if it's
very dirty, oxidized or sulfated.
Remember that there is a metallic coating that prevents or slows corrosion,
so don't use rougher materials like sandpaper or steel “wool”.
