How to sculpt along a specific axis? I have faced a problem in sculpting: When trying to grab, sculpt result ends up traveling along the X or Y axis while trying to be pulled down Z axis. 

Is there I can set Blender to sculpt along the Z axis, or another single axis, so that I can sculpt better?
Some brushes have this option in their properties panel, but the grab brush doesn't seem to follow its instructions, and it seems to be always view-related.