Just put it in a box, wrap it up like a gift, put it in a bag, and leave it unattended in a McDonalds for a minute.
Your theory is correct.
Honest truth. I was staying at a lady friends in NYC several years ago and helped her to clean out her apartment. One of the things she was discarding was an old umbrella.
Just to see what would happen I put the umbrella outside her front door which was at street level and it disappeared in less than 5 minutes.
Funny and apropos - took me back to when stationed in Italy. if you had something you wanted to get rid of, all you had to do was set it on the walk by your car and go back in for a minute as if you had forgotten something. Even trash bags filled with trash would disappear withing a minute or two.