Segmentation smooth

Hello! I have a dataset of chest CTs. Here is what I see when I open them with 3d slicer:

This segmentation has some sawtoothes both in the label map and the mesh.
I want to get smooth contour and I saw some videos use the ‘Gaussian smooth’ in ‘Segment Editor’.
Is this a nice way to maintain the segmentations’ information? Since they are made by radiologists.
Also the ‘Gaussian smooth’ has the ‘standard deviation’ option. How should I set this in a reasonable way? How many milimeter should I choose?

ask2

Thank you!