I think Bach (for example, 2-3 inventions) will help you mostly in hand coordination and understanding of music .
But if you want to develop technique (strength, speed, wrists, weak fingers, stretches, etc. ) with fast results, try playing Hanon for a while, mostly his part three, but also some of part I and II.
However, you will see that many people in this forum will tell you doing Hanon is a stupid thing.
Javier