Keeping meat in salt water
I can only partially answer your question but still:


Cold : yes, absolutely
Salt : yes, that would help.
Water ??? No.


Bacterias love water. When trying to preserve meat you actually want to do the opposite, you want to keep it dry. That's how curing works actually. Absorbant paper is often used to prevent the meat from deteriorating by swimming in its blood.

You mentionned pickles, pickling works thanks to acidity. And pickling meat isn't a good idea, as the acid will deteriorate the meat fast.

Now I will NOT tell you here that keeping meat 1 week in the fridge is a good idea or guarantee that it's safe. But cold and salt will definitely slow down bacterial growth.

Lastly, keep in mind that what's most important is to know what meat you bought. I mean who you bought it from, how it's been processed and preserved...