My dad is an electrician and I have installed too many to count outlets, ceiling fans, switches, and breaker boxes. Never knew about this hidden tool.
Wow. I haven't watched content from that channel in a minute. I never knew about the stripper function of those slots either but I have such a variety of strippers and pliers, I wouldn't have even thought to use the slot.
Also, nine times out of ten, I used to replace outlets with live wires. I'll kill the circuit for a ceiling fan or something, but replacing an outlet...hell, even circuit breakers themselves, I tend to do it on live wires/panels.
It's not a risk that I'd recommend that anyone take as a novice or a layperson. I'd just done so many over the years, I know what NOT to do to get myself fried.
At my age now and my sense of mortality, I do shit more carefully now. Pa Pa gotta be around for them crumb snatchers.