I found a blog post and it said...
Salt in the soil can keep plants from growing in that spot for some time – both weeds and other plants – so it’s not an ideal spray for gardening):
It works best when you spray the weeds on a sunny day when there’s no rain in the forecast for a few days.
Hi Jerri, this is the recipe we use to make our own weed killer
Hi Jerri - The struggle is real, isn't it?!? This is the most effective all-natural weed killer DIY that we use. It's even been featured on Hometalk! Hope this helps! Hugs, Holly