Eating lemons once aday...?!
Answers: do you think that eating lemon with salt once aday bad for you?
As the citric acid is involved in the body metabolism ('Krebs circle') it is good for you (for everyone). You can enhance it by eating an apple per day. Both, however, should be 'Bio'.
For your teeth yes. It wears off the enamel on your teeth.
Only for teeth
It depends on what affect you are going for. Are you looking to get the Vitamin C? And why add the salt? And do you brush your teeth after the fact? Getting the V-C is easy if you just want to squeeze it and drink it. The salt, i don't really know. But make sure to brush you teeth BEFORE you do this ritual. Brushing you teeth after that fact is like using an abrasive material on glass, it gonna scratch it and eventually break it down.
bad for your teeth and it makes your sh*t green, like any other citrus
well i'm guessing salt does