1) Wipe it down and hope you don't click something stupid.
2) Turn off the computer.
3) Disable the touchscreen.
I want item three, but there seems to be no Unity control panel for the touchscreen. I couldn't find one so I opened the Swiss army terminal and typed xinput.
Reading down the list is simple enough, id=13 is my touchscreen.
The command is xinput disable 13 or whatever number you need. Turning it back on is just as simple with xinput enable 13.
Obviously, I am not the best Linux user, but I like to share tidbits that make things easier.
Now clean that monitor.
