When I replaced our stern navigation light, the pushpit, I noticed that the cable moved quite freely and was not sealed / gooed to the pushpit: so at least our boat was different than Symphony's suggestion. I would suggest studying current pushpit mounting points on your lazarette and figuring out if an existing cable could be used to feed a mousing line or if electrician's fish tape could be used to feed a cable through pushpit tubes.
Looking things from lazarette side will also be very helpful on deciding gland placement if you end up using that way.
BR,
Tommi
s/y Anniina