Glyphosate plus ammonium sulfate may be more effective. Repeat applications may be necessary since there may be dormant tubers in the ground.

Here is a link that might be useful: Nutsedge control

Yes, be patient!!!

Will the rock salt or dry molasses be effective in July here where temps. are between 95 and 100 degrees?

Anne -
There are certain times of the year when nutgrass is suceptible to herbicides. Read the labels, follow the directions exactly and be patient.

"Repeat applications will be required for control, as there are always dormant tubers not affected by the treatment which can sprout later in the season."

DO NOT USE SALT! You will kill everything and it's hard to get rid of - not impossible, but it's a solution with long-term problems attached.

I doubt molasses would do anything.

Weed block isn't thick enough, you need something like 30 layers of newspaper with the glass sand on top to even slow it down. I would use vinegar at as strong a concentration as possible - at least 15% acetic acid and preferably stronger.

I keep pulling mine, but don't have a lot so haven't worried. I do remember pulling that weed and putting it into a zip-lock bag and laid it down on some grating. Forgot it and at the end of the summer I found it again, alive and well setting in the hot sun all summer without any soil or water. I do remember our local Radio Garden person saying there is a herbicide that will do the job but a small bottler runs around $50 and will last a very long time so you would need to find some one else to share the use and cost? I don't know if salt would even slow it down as it seems to do well even on the coastal areas.