you are correct the clippins will not root. BUT the grass seed mixed with these cuttings is germination
The grases flower & produce seed several times a year

Sorry, that's not correct. Grasses like Cynodon (Bermuda Grass) can and often do root from stolons (above ground horizontal stems). In fact, this is a commercially-viable way sometimes used to propagate certain grasses.

Excuse me but grases most often grown in WA (Blue grass, Rye Grass & Fescue) will not be propagated by clippings but by seed or division.
Chrisf could have prevented the confusion if had been specific as to grass type

Both are correct. Some grasses, such as St. Augustine, will root from node cuttings as well. We stomp them into wet ground all the time, to fill in 'bald spots'.

Janie