My wife & I had appointments this afternoon to get vaccinated, so I didn't get to this as soon as I had hoped. There was a comment on the download page about the app hiding folders from Windows so subsequent cleaning might delete them, and I was concerned that this false info might turn some folks off from giving it a try. Turns out however that if you skipped it you didn't miss all that much IMHO.
BulkFolderLocker Pro is a small app that sets restrictive access permissions to folders you choose to lock -- when you click on a folder in Explorer to view that folder's contents, you get a message from Windows that access is denied. It's similar to trying to access Windows\ Temp\ on a fresh install, only you can't click through it to access the folder's contents like with that Temp folder. You can get access by taking ownership of a locked folder -- right-click the folder -> Properties -> Security Tab -> Advanced. It's something to keep kids, guests etc. out of folders you've locked, as long as they don't try too hard, and if they do take ownership of the folder it's obvious afterwards.
The app takes up just short of 13MB in Program Files (x86)\ BulkFolderLocker\, with a single .ini file added to ProgramData, and 5 files added to Users\ [UserName]\ AppData\ Roaming\ [they are not in a folder]. The registry gets a new uninstall key.