In engineering, we have a typical response to upper management’s often “impossible” requests:
We can make it cheap, fast (rapidly developed), and high quality,
Pick 2 of the 3…
Cheap and fast: Go to Pep Boys or a lawnmower repair shop, get an old-style manual choke cable and knob.
(If using outside, be sure to soak in grease and spray lube on every so often) The friction in the cable will hold the switch in the position you want most times.
Relatively cheap and fast: The bicycle cable, and have to make sure there is a “detent” spring somewhere to hold the turnout in place.
Fast and high quality: Air driven from Ez-air, use a cheap air tank for air supply. They have pneumatic toggle switches, all parts are weatherproof.
I’d go the last route. I have gone one step further on my layout, use electric solenoids to throw the switches, and DCC accessory controllers to run the solenoids. Look in the track section on my site: www.elmassian.com
Regards, Greg