[Bob Bidonde]

Safety wire, cotter pins, lock washers, Nylock nuts are security devices that prevent the loss of fasteners that become loose. They do not maintain tightness. The safety wire and cotter pin are positive security devices.

Thread locker does retain tightness and it is useless to retain fasteners that become loose.
The friction from torquing and interference fit nuts (AKA self locking nuts) retain tightness. Interference fit nuts also prevent the loss of fasteners that become loose.