Can you use ammonia and table salt to kill large area of weeds?

Yes, also I have always used vinegar and salt.

I use rock salt however, I am not planting in that area. I'm not quite sure if there is any long term effect.

If you do, the ground will be unsuitable to grow anything else. Perhaps spray vinegar? Pour boiling water? Use a small dragon torch?

you can as well as vinegar,however if there is grass,plants,trees,shrubs,it will kill that to. https://www.hunker.com/12459451/how-to-use-ammonia-to-kill-weeds

White vinegar on a hot sunny day works

I use a mix of 1 gallon white vinegar, 1 cup epsom salt, and 3 TBSP blue dish soap (like Dawn Original). Spray on plants when it isn't windy and won't rain for at least several hours. It is a non-toxic way to kill weeds and grass. Don't spray plants you want to keep, and also note the places where you have sprayed will likely not be suitable for new planting unless you amend the soil due to the high acidity of the vinegar.

I would not recommend using ammonia as it is highly toxic.

white vinegar, cheap and chemical free!

Please, do NOT use salt. It will "kill" the soil so nothing will grow and secondly, it seeps into the water table.

Use epsom salts. Magnesium sulfate, a fertilizer. Everything is a chemical. Vinegar is acetic acid. Salt is sodium chloride.

Hi! No, I wouldn't. I have used vinegar and hot water on some areas successfully. Digging them up is also very effective. Good luck!