There is always, except perhaps at one common-mode-point,
an imbalance between the gate charge (which includes Cgs
and Cgd) of the N and P switches, for a net charge bump on
any switching event. Nastiest is the turnoff, where you take
away one of the dissipation paths for that charge.
Some specialty switches advertise low charge injection
and anti-pop type design. Slowing the gate edge helps
at least with the perception and high frequency content.
Attaching shunt resistors (and maybe capacitance, so
long as normal frequency response isn't compromised)
can be a band-aid. If you feel a need to roll your own
you could, perhaps, use some of the ALD discretes and
a gate drive of your own construction (e.g. a controlled-
ramp op amp drive, or slow RC, or ...).
You could also consider instead of the simple shunts,
some sort of (say) FET shunt which blanks the audio
path for the duration of the switching event.