What I really need is a "Refresh Desktop" option when I right-click Desktop
IMHO that is not the best solution, look at your logs X or XFCE is failing somewhere.
When the problem is fixed there is no need for a work around. Setting up
refresh desktop just to shadow a problem is a windows approach, forget the
problem kludge a work around.
The way this works is there is the X server, then the WM/DE that sits on top
of that. The core, mouse,screen and keyboard are from the X server not the
WM/DE. To the basics of it all everything from the GUI runs as a command.
The other way to test something is to run the command from CLI and
watch the output or pipe it to a file.