ER-20's? why would you want to sleep with those? LOL, save them for concerts and movies. I'm a side sleeper usually, so I can't sleep with anything in my ears, save maybe foamie ear plugs. I don't even sleep with customs in.
Oy, I'll be in Chicago in less than 3 days.
FYI, I noticed that the Hilton website allows you to add on amenities. Like extra towels, pillows, and blankets for free. Also allows you to add on a folding bed for $25 or something for King rooms (not doubles), might be better than a bathtub.
https://ohare.hyatte-concierge.com/Welcome.aspx
-Ed