It depends on the hole, but I find that after squeezing all the air out, most holes don't make much/any noise while you use them. But I think it does make a noise when you initially squeeze the air out.

Washing could be a problem if you share a bathroom.

Clean up is going to be particularly difficult, especially if you're sharing a bathroom. If your rooms are shared I would go so far as to say it's not worth the risk of possibly getting caught with (I'm assuming you don't really want him or anyone else to know you have an onahole as you're worried about sound). If your rooms are separate however, the sound will probably be less than that of you actually using your hand. While this depends on the amount of lube you're using, I've never heard much even when using a generous amount.

Hope that helps. Pic unrelated as well.

Well, when I started with onaholes, I had people in the house 24/7. I found a way to get to the bathroom without anybody seeing anything suspicios in me, I just put the onahole in between my legs inside the pants, and walked slowly to the bathroom, cleaned it, and you need a towell just for yourself there too. As for the noise, if the people who you live with have a light sleep, you could get the risk of getting heard. I'd recommend the secret twin tales onaholes, since they do not make as much noise. I'm using the secret twin tales 2 and it's quite silent.

Uhh if I were to tell you how onahole sounds (without squeezing the air out), take a sip of water and blow your cheeks as fast as you normally stroke. Let the waters pass through the teeth as you blow your cheeks. At least thats how two of mine sounds like :P