I would be more incline to think our sun has a sinster sun companion then a 10 th planet. Most of the sun system are made up of binary stars 2 or more. This solar system is one of the rare one with a single sun. There just migth be a dark dwarf star that is obriting with our sun and causing the preturb that send stuff into the inner solar system every 250000 years or so.
Something to think about.
John
KL7IFP