Exactly. The best way to improve a cuppa made with teabags is to pour it down the sink.
AIUI the original US thought was that, if you've 'stewed' your tea by leaving it too long (unlikely in the US, where I've never experienced water hotter than lukewarm), you can rescue it by adding a little salt to counteract the bitterness. But if I stew the tea, I just throw it away and make fresh, it's not as though a couple of teaspoons of tea will break the bank.
For the benefit of overseas readers - how to make a cuppa (it's not rocket science) - you will need:
A kettle; a teapot; some loose leaf tea (M&S Extra Strong for me); milk; cups or mugs for drinking from; sugar (no thanks, but optional).
1. Empty kettle and refill with sufficient fresh water to fill the teapot.
2. Bring to boil.
3. Fill the (empty) teapot.
4. Pour back into kettle and reboil.
5. Add a couple of teaspoons of tea to the teapot (mine's a 1l pot, if you're using a larger one scale up accordingly).
6. Pour on the **boiling** water, stir vigorously and leave for 6 minutes (timing can be adjusted for strength).
7. Add milk to the cups/mugs and pour through a strainer. Some will insist that milk must be added after the tea; I won't argue, but they're simply wrong :)
8. Enjoy!