This:

Grit from 100g bag of Tesco "washed and ready to eat" salad
rinsed out of a 100g bag of this:

Label from Tesco "ready to eat" salad

"...washed and ready to eat"
Washed?
Maybe. Briefly, from the looks of it. Very briefly. All I did was put the contents of the bag into a bowl of water & swish them around a few times. I was going to pour it all into a strainer until I noticed some grit in the bottom of the bowl, so I took the salad out by hand instead. You can see what stayed behind.
Ready to eat?
Not as far as I’m concerned.
Yuck.
What does the “strong” on the label refer to?
I think it relates to the percentage of rocket in the salad. The higher the rocket content, the stronger the taste. Not sure, though.