We do exactly the same. We treat them like a dangerous item. Never did with ordinary secateurs.
I have read the same about leeks. I have replanted many bases of stems with the roots. The best I have got is a short bit of stem, which took forever. Best to either just plant lots or grow ‘perpetual’ varieties.
Thanks for the feedback, I am just experimenting.
I’ve got some home saved leek seed I’m experimenting with, if it germinates I’ll send you some.
You are a gentleman. Thank you.