Ther is a tool used in the aircraft industry for wirelocking. it is basically a pair of locking pliers with a knurled nut on a twisted rod in the centre of them. You lock the pliers on the wire, pull on the knurled nut and the pliers rotate giving a twist to the wires. They may be a bit pricey and perhaps difficult to find but would do a really good job for you. They would be called "wirelocking pliers". JohnB