Once the smell has gone, its gone forever.
And no, there is no real way to artificially add an aroma.
Maybe flavoured rolling papers will make it taste better?
Perhaps try putting a bud or two in a jar with some dried mint leaves as an experiment, if you like minty buds that is.
Whatever you do, do not try it with the whole lot in case it is horrible.
Lemon juice will just make it moist and won't necessarily make it lemony. Again, experiment with a bud or two. Maybe some vanilla essence too?
Hope this helps,..........
Organoman.