Gavin's all day punishment

What Gavin did yesterday is something that I will never forget nor let him forget.  As many of you know, we are living in a house that belongs to our friends here in Syracuse.  We have been living here for a little over a month.  Yesterday (Saturday) was cleaning day and I was picking up around the front room so that I could vacuum.  I straightened up the couch and lifted the pillow and to my alarming surprise, saw a thick blue ink mark on the microfiber couch.  Now mind you, this is not our couch so you can just image my horror!  I was running around the house with my hands in hair, ready to pull it out, and thinking about what I could use to get it out.  Gavin at this time was downstairs watching TV.  I asked him to come upstairs.  I pointed to it and asked if he did it. With his head turned down a little and his little blue puppy dog eyes looking up at me, he said yes.  I asked him why and his reply was "Because I did!"  I was livid.  WHY!!  I went on about this not being our house and he can't go around using couches as paper.  Of course, what three year old is going to listen to me running around the house with my head chopped off and going off about who knows what?  Exactly!  I got online to see if they had any ideas about what to do and they mentioned a few things.  The one that had the most votes was Purell hand sanitizer.  I had some in my purse so I thought I would try it.  Voilla! It came out.  I had to scrub and scrub and scrub.  By about 4 pm, the stain had disappeared.  I was relieved.  That whole day, Gavin was not allowed to play with any of his toys.  He had to help me clean the house and stay by me all day.  It wasn't fun for me...but that was the point.