From the submitter:
"A Chinese charger for an RC car was broken beyond repair and I had an extra cord lying around. Yeah, it's fugly but it works... and yes, the other hole is now plugged from inside the charger so it is actually safe too!"
The only issue with this "lock" is that it's less of a security mechanism and more of a test of strength between you and the person coming in. If a 300-pound linebacker gives the door just one good yank, he'll probably send you flying from the toilet seat with who-knows-what strewn all over the floor.