My DS is 17months and completely obsessed with the toilet too. His favourite thing to do is to stuff it with toilet paper. Also lost a bottle of shampoo and his sisters hair clips!

I tried putting a potty in there but he's much more interested in the toilet of course! I just keep re-inforcing that we don't touch or throw things in but we can sit on it, hopefully it sinks in soon before we lose too many more things to the loo!