I don't understqnd the cucumber thing either, and I am agog to report that I've found it to actually work. Could be a fluke, but I was losing it over the bitter CSA cucumbers. And then it vanished when I started trimming ends and rubbing.
Anyway. The old timey thing I still do for nostalgia alone is scrape the surface of steaks with a dull knife. To remove, you know, dirt.
[**I think the concern is that the butcher, or store, is selling you an item has fallen on the floor].
As I was taught: if you rinse it (like we do with chicken), you will rinse away the beef juices. Hence: scrape.
I also clean my greens for a long time in heavily salted water, much longer than is actually required for today's market greens.
One flank of the women's side of my ancestry meticulously removed the green leafy aspect from 100% of the veins of collard greens. Repeat: ONE HUNDRED PERCENT. No veins. None. Not in any single leaf of green.
I do not do that anymore . . . .