You may find that lubing alone may not fully eliminate all the rattles on costar stabs.
Or the rattles just gone for awhile, then it comes back after using a period of time.
Here is how I deal with the rattles besides just adding lubes.
First, we must know where the rattles come from.

As shown in the image, the rattles come from the collision between the insert 's hole and the stabs wire, which marked in red lines.
Why are there collision? Because the wire usually doesn't fit in that hole.
There are tiny gaps between the wire and the hole (in top and bottom aspect)
So, to effectively eliminate the rattling, the goal should be minimizing the gaps and make the wire fit in better.
Band-Aid Mod 
Yeah, it's Band-Aid Mod, not just for Cherry stabs


cut a little piece of fabric Band-Aid and cut it to a more rounded shape (bad example in the image, which is square-shaped)

Then carefully stick the Band-Aid piece to the stabs insert as shown above.

After that, you may want to apply some lube here. I use Permatex dielectric grease here.
Beware, the amount of lube should depends on how tight the wire fit in the insert hole after adding band-aid.
If your stabs become mushy, try wipe out the lube and reduce the amount, or use a less viscous lube.
Here is the effect:
https://www.bilibili.com/video/av22910824?zwIn the video, Right-shift and Enter are lubed without band-aid mod, while others are lubed with band-aid mod.