外有虛名 Cool Enough To Live In
卻說大聖到了瓶中，被那寶貝將身束得小了，索性變化，蹲在當中。半晌，那邊蔭涼，忽失聲笑道：「這妖精外有虛名，內無實事。怎麼告訴人說這瓶裝了人，一時三刻，化為膿血？却说大圣到了瓶中，被那宝贝将身束得小了，索性变化，蹲在当中。半晌，那边荫凉，忽失声笑道：「这妖精外有虚名，内无实事。怎么告诉人说这瓶装了人，一时三刻，化为脓血？
逐句解 Line by line
Now when the Great Sage got inside the bottle, the treasure bound his body down small, so he simply transformed and squatted in the middle of it.
束得小了 puts 得 in its light de, hooking the result onto the verb — bound so that he became small. 索性 is a lovely piece of vernacular: might as well, and be done with it. He is not fighting the bottle; he is settling in.
After a good while it was shady and cool in there, and he suddenly let out a laugh: "These demons have a big reputation outside and nothing behind it.
失聲笑 — a laugh that gets out before he can stop it. That is the second time in this chapter a laugh has escaped him without permission, and the first one cost him his disguise.
How do they go about telling people that this bottle puts a man inside and in an hour and a quarter turns him to pus and blood?
為 is wéi, to become — the copula band, not the wèi of doing something for a purpose. And the whole phrase is quoted: the previous chapter has a demon saying almost exactly this, 化為漿水, turns to slurry. Wukong is repeating the sales pitch back at the product.
The chapter has just put its hero inside a magical cosmos-in-a-jar, and his first reaction is that the air-conditioning is pleasant. This is exactly the note the book wants: not defiance, not terror, but a consumer complaint.
一時三刻 is a real measure and worth pausing on. A 時 in this system is a double hour, and a 刻 is a quarter of one — so the advertised time to dissolve a man is about two and a half hours. The demons quote it the way a kettle quotes a boiling time.