There needs to be a reference to the silent uninstall script file in your command. When you uninstall from a command line with a -r at the end of the command line, the uninstall script will be recorded with an .iss file extension. The, update your command to reference the .iss file. Note that there is no space after the "-f1"
"C:\Program Files (x86)\InstallShield Installation Information\{61DF41B1-9877-4906-80C4-09941A05BD77}\setup.exe" -f1C:\full_path_to_uninstall.iss -runfromtemp -l0x0409 -removeonly /s
- Bob Hickey