I believe you will fnd just about any salt will work in LA. You will also find no need to plant expensive seeds for greenfields. A clover/rye grass mixture will work just fine and ideal time to plant is Mid-late September.
The gym bag idea is fine and a tow sack will work just as well. I prefer to put my salt in an old stup in cly soil. It won't take long the "lick" will be huge and the deer actually lick the soil. I do believe however, you will find that is great for a camera but of little use for hunting purposes. I also suppose you are aware the rut in LA peaks in early January?
Good luck and enjoy working with your own property and remember this. Deer are edge animals. An S shaped food plot will beat a square one all to pieces.