He filled it with water at the dock and it sunk OR he threw it in a dumpster near the docks....
I'm from a seaside community. Things thrown into the water near docks tend to wash up. I think HKS's MO is to use the toilet to flush away whatever he doesn't want found.
Ok...I'll go with that. I flush my old meds down the toilet...Ya know..The ones that the doctors says: Take this and if it makes you sick, take these. Just love when they pull that cr**. Neither was an antibiotic. Those I take when instructed to do so.