Osx selective sync trigger deletion

on Mac OSX, if you uncheck a directory to not sync it, how can you expedite the process of removing it from the local file system? How long after it has been unchecked is it removed from the file system? Is there a way to perfom this action immediately?

It happens with the next sync run which is normally started right away. Depending on how many things need to be synced it can take till the end of this run till the folder is deleted. Do you have a different observation?

right, but it's different on OSX, than on GNU/Linux?

..,cause on GNU/Linux, the files are not deleted right away; they go into a hidden trash directory

This is no "normal" behavior of the sync clients. There is no trashbin included in the desktop sync clients so this is something specific to your Linux installation (maybe a tool installed?)