Unless very carefully applied only to the unwanted plant growth ("Weeds") that salt water could kill off everything growing which would allow more "weeds" to grow back, before the soil recovered from that so the more desireable plants would grow.
I would first mow that yard and have a good, reliable soil test done. Contact your counties offiice of the Universtiy of California Cooperative Extension Service and inquire about having that done so you know what your soils pH and major nutrient levels are. Some "weeds" grow better in soils that are not healthy enough for grasses to grow in.
Then correct the soil according to the soil test, keep the yard mowed (that prevents many "weeds" from developing seeds and that can lower the amount of them) at the proper height which can help keep "weed" seeds from germinating. Maybe this fall you could seed some more desireable grass seed out there to help fill in the bare spots.
There are no sprays that would really kill those "weeds" that would be safe for you pets, or you.

Here is a link that might be useful: UCan CES

UC doesn't do soil tests. Hasn't done so for years. But each county Extension Service office can suggest a professional lab that's nearby.

First you have to get rid of the overgrowth of weeds if you hope to do anything. As Kimmsr suggests, mowing will grind them up and lower the level, or you may need to get someone to come in and cut them off and carry away. After that, keeping it mowed will control a lot of weeds while you get your lawn and other landscaping back in order.

You can use selected herbicides to help clean up problem areas once the overgrowth has been cleaned up. Glyphosate is particularly useful because it will remove most anything and it breaks down quickly. Used according to the label directions it is highly safe and presents far less risk of damage than trying to kill the weeds with salt. Just keep your pets away from the treated areas until the pesticide has thoroughly dried and at least 24 hours.

Thick mulches, black plastic, layers of newspaper or cardboard, tillage, hand weeding, herbicides, soil amendments, planting a thick stand of grass or other plant selections, and water management among other things will all provide you with results and combining them will work even better. You'll have to choose your preferred methods based on your physical abilities, how much time and money you want to spend, and your personal preferences for appearance and what you do or don't like to do.