HI @Tamunathor ,
You might want to try changing some Scene Settings; increasing the Gravity will have more likely the effect you want then changing the Mass.

Things will also fall faster, but you can compensate that with the Speed in the Rigid Body World, or simply changing the FPS, after Baking the Simulation.
There is also a Deactivation checkbox in the Rigid Body Settings, you can try.
Play around with different Settings. Change only 1 Setting each time and make sure the Cache is cleared between tests.