Can you please explain how your character get stuck? I've never really heard of many people experiencing anything like this. It would be better to fix the cause of what is making your character get stuck than to just add a dispose command.
Do you remember which item caused getting stuck? I believe there might be an issue with the 'Pink Jester' magician hat.
Pink Jester Hat (I sold two of these), and the Beginner Book. Maybe a Brown Jester Hat as well (not too sure on that one).
This has happened to me several times actually, but all I had to do was close the shop and reopen it and I could continue to sell.