So, you want to hide some things so that noone ever be able to find them? If it so, than grab your valuables and listen to me, because I know what you have to do. It's wery easy.
First - take your stuff and put it into a sock.
Than, leave the sock at your bed overnight.
At the morning your stuff is no more. Noone will find it again, infact, even you!
Nobody knows, how it works. Maybe those socks are entering the pocket universes or teleported straight to hell, where are used as a fuel for torturing sinners. Some scientists suggest that socks are larvae of multydimmentional creatures, and when they're grow up they morph into 6-dimmentional state which can not be percieved by humans. Conspiracy theorysts suggest that it's a part of of a plan of certain secret worldwide organisation of disfunctionig the work of left and right brain hemospheres of people by forcing them to wear only one sock. Or maybe, we all live in an episode of Twilight Zone and nothing really makes any sense.
Some researchers optimistically claim that there's a very small probability of your socks appearing randomly back in your room over decades after disappearing, but their studies are claimed to be contraversial.