I have seen/managed several different types of LOTO programs and I would not necessarily call one "good" simply because it requires personal locks. Although I agree with you both on the 1 lock/1 person rule as a best management practice.
Master locking/Operations Locks have a long history of being very effective in Power Genration, Trans and Dist. Signing on and off to a LOTO can be very protective provided the system is good. i've been witness to LOTO's that include 50+ people. although this is not excuse to sacrifice safety, 50+ locks could pull a circuit breaker Lockout device off.
Although given the option, I use my overlocks/overtags!
