I have about the same size boat with pump out head and it works just fine.
My marina has no fee for slipholder pump outs, so we just made a habbit of
getting the pump out at the same time we fuel up.
In a 23' boat, the configuration is likely to be a modified port-a-pottie,
that is clamped in an enclosed space in the cuddy, usually with a privacy
curtain. The pump out and vent hoses are run up to the starborad side rail,
while the gas fill is on the port side. If no pump out is available, one
could disconnect the hoses and hand dump the pottie, but this has never been
needed in my case.
(The boat is a Searay 22' weekender)