"Go ahead frisk me" -
Even though this seems unimportant it could actually have a deep meaning to the emotions portrayed in the book. I saw this as something he said in his mind, i thought it was in his mind because, in the prison the guard would demand more respect of the "children" I mean prisoners. Thus making him feel the courage to say so but not to act upon it because i think he knew the guard would get at least a bit angry at him for disrespecting them.
"Double time" -
This also has a "double" meaning :). And this double meaning is, the prisoners see double time with different meaning depending on the context. For example for the first time wee heard the guard yell double time the prisoners raced to see who could get to the barracks first , but maybe next time they will be angry and just go the same pace. You never know life and book are always full of surprises.