Delphi doesn't "cache DCU files" except in memory when it's compiling.
If you have new properties that you can't access in the new components, you haven't properly uninstalled the old ones, and the IDE is getting its information from the old designtime/runtime packages.
You need to properly remove the old packages and dcus before installing the new ones, and then properly install the new packages into the IDE. The DCUs by default are installed in the SecureBlackBox\Sources
folder after installation (they're created there when the packages are compiled and installed).
You may also need to remove the compiled package files (.dpc) from your computer before installing the new ones. Search your computer for *.dcp
files; you should find several of them related to SecureBlackBox in your My Documents
folder. They should be removed before installing the new versions as well.