As referenced in that thread, James Ghetty cannot be used for the effect for Accidental Reunion
Ghetty can be used to pay the initial cost for the Dude at the beginning of Serendipitous Arrival, but not for the 3 ghost rock at the end of the shootout.
Ghetty can be used with the Clown Carriage, as playing the Abomination is part of the cost.