Vanish will see anything displayed on your browser that's highlighted in an editable text window. One is provided for convenience on the Vanish download page (see Figure 2).
Figure 2 Create a Vanish message
Highlight it, right-click the highlighted text, go to Vanish > Create Vanish Message as you see in Figure 2.
If you see two menu bars, you aren't imagining anything. I had a remote control session to my Debian/KDE4.2.2 desktop going on while I was running Vanish from my Kubuntu/KDE4.2.2 netbook (see Figure 3).
Figure 3 Vanish encapsulating a message
Figure 4 shows a message in cryptotext “encapsulated” form after Vanish processing.
Figure 4 Vanish encapsulated message
Figure 5 Vanish decapsulating a message
Figure 6 Vanish decapsulated message
Here you see the original plaintext message, precisely as it was entered.