I think binding could be obvious to close family and friends. Of course, distant friends and stranger, I don't think are staring at your chest to notice anything different, lol.
With me as well, I wear baggy clothes, which makes it even less obvious to family that I'm binding. Plus, even if they do notice, they aren't going to say anything, because that's kind of embarrassing to be like, "yeah so I was staring at your chest, and I noticed your boobs aren't very prominent anymore. Care to tell me why?"
Yeah, I don't think anyone is going to say that to you. And if they do, something is seriously wrong with them. I'd reply, "stop staring at my chest, weirdo." even if it was my mom I'd say that

As for washing it, I think soap and water is find. It's a tough material. I wash mine with the rest of my clothes.
However, I also got the 997 in black, intentionally because I knew that that way if anyone say it, it would just look like a tank top. a weird one. So I could just tell them I like to swim in it. I'm not worried if someone found it in the laundry. although I do do my own laundry.
Best of luck!