Forcing a new flash based screensaver

I was using this back when I was still setting screensavers:

# set /System/Library/Screen Savers/Flurry.saver
# tested OK on 10.9.5 - no need killall cprefsd etc

if [[ `ioreg -rd1 -c IOPlatformExpertDevice | grep -i "UUID" | cut -c27-50` != "00000000-0000-1000-8000-" ]]; then
    macUUID=`ioreg -rd1 -c IOPlatformExpertDevice | grep -i "UUID" | cut -c27-62`
fi

defaults write ~/Library/Preferences/ByHost/com.apple.screensaver.$macUUID.plist moduleDict -dict path -string "/System/Library/Screen Savers/Flurry.saver" moduleName -string "Flurry"

Obviously you can also use Casper's fixByHost function.

You can also check the current saver:

defaults -currentHost read com.apple.screensaver.plist

@Goober22 to add my experience to what @pete_c has posted.

1. Flash based screen savers will use up CPU etc when screensaver is loaded & may kick fans in & use more energy than normal idling.
2. They cannot be ran at the login window, (if a want).