So yeah make sure you clean it with water and soap but importantly remember to let it dry. i give it a light pat down and then if I can let it air dry prvenets any unwanted mould etc growing.
In terms of where to store just find an out of the way place in your room that you can be sure bno one will look maybe a bottom drawer a box etc. Its tedious but if you don't want anyone finding out then you gotta do it buddy.
And with the bottom cap off it'll stillmake noise but not as much noise but you do take away a biot of the suction effect, also be care if you cum inside as it'll pass straight through. 
Hope it helps!