Everything from coat hangar wire to fishing line and weights have been used to manually throw turnouts.
Whether or not you use the Peco spring that "latches" the points is going to make a difference on how you set up the manual throw. Because of the spring "latch", you can just push them by hand if you choose and can reach.
Commercial solutions include Caboose (and other) ground throws which can be made to work from a distance with some kind of push/pull rod/wire. Humpyard is in this category also, as is a blue box resembling a small Tortoise that has been recently advertised. Caboose Industries throws are much cheaper than the other 2, but will take more engineering to hook up a push/pull system.
And you can roll your own using model aircraft components, fishing line and springs or weights, coat hangar wire, etc. If you remove the Peco latch spring to make the throw easier, make sure your device has sufficient throw and some spring to hold the points firmly against the stock rails without bending anything.
Hope this helps