The only temporary links available other than from some old guy are the ones available from MB for use with the new style chain tools, about $75 for three links needed!
But here is what I do! The duplex timing chain is essentially two separate chains both with inner and outer chain plates with an additional chain plate between them.
Once you get the old chain broken/separated you'll have the last link as two separate parallel chains and the center chain plate will be gone (you remove it when you pull that link that you ground the ends of the two pins off)
Take your repair link and put it through the first parallel chain, then take a small rubber O-ring and put it over the two pins, then swing the second parallel chain ends in place and push the repair link all the way through.
The O-ring will reside in the place where the center chain plate usually resides; it then runs in between the parallel chains and the duplex sprocket teeth so it doesn't touch anything.
The tension of the stretched O-ring holds the repair link pins from moving side ways and potentially jamming, it's easy to get on and off and even if you loose it down into the timing chain chase its not like the spring steel clips ending up between the chain and a sprocket.