When you connect USB-disks, camera's, GPS devices and similar to the Mac several invisible files and folders will be generated; when putting files on it several more invisible files will be created.
When you delete files, they are moved to the folder .Trashes still taking up disk space; to get rid of them you need to empty the Trashcan.
When the device is connected to a Windows PC the invisible files will be visible.
These phenomena are generally not wanted, and in certain cases they even can disrupt the proper working of the device.
To prevent this the program CleanEject was created. This program erases the following folders and files:
After removal the device is disconnected immediately (when you would do this in Finder, some of these files would reappear).
The program operates only on FAT16 of FAT32 formatted disks; in the case of Mac OS Extended formatted disks the removal of these files is usually unwanted. That's why CleanEject won't show these disks.
Using the program is simple: start the program en select the disk(s) (the program selects them all by default) you want to clean and disconnect; click the OK button and the tasks are executed.
It's also possible to use CleanEject in a different way: drag and drop the disks you want to eject onto the icon of CleanEject; they will be cleaned en ejected without showing a dialog box. (place a shortcut to CleanEject on your desktop for your convenience)
With large disks containing lots of folders and files it can take a while because the whole disk is searched for files that will be removed. When the icon disappears from the desktop, you can physically disconnect the device.
Note: some devices (like the Garmin Montana) automatically reconnect after ejecting. You can prevent this by letting CleanEject not to eject the device, but to de-activate it instead. It somewhat the same thing: the volume is closed so that file corruption cannot occur; the difference is that the device will not be switched off.
This can be accomplished by putting a text file with the name unmountme.txt in the root folder of the device. When you have a Garmin Montana it is sufficient to place this file on the SD card only.