How do the words peroxide, long, low whistle, Texas and Dairy Queen involve any of the characters and events from Chapter 5 of The Outsiders?

These words are all related to Johnny and Pony’s experiences when hiding out. 

Johnny and Pony go into hiding after Johnny kills Bob in the park to save Pony.  Dally helps them go on the run, telling them where to wait for him.  Johnny uses the whistle to communicate with Pony when he goes off to go to the store.  It is something they use to contact other gang members. 

heard someone coming up through the dead leaves toward the back of the church, and I ducked inside the door. Then I heard a whistle, long and low, ending in a sudden high note. I knew that whistle well enough. (Ch. 5) 

Once they are in hiding, they cut their hair and die Pony’s hair with peroxide.  It is Johnny’s idea.  He is thinking of ways to avoid them being recognized, because they are two greasers on the run from the law.  Pony does not like the idea of changing his hair, because it is part of his greaser identity.

Dally tells Johnny and Pony that the police are not looking for them because they think they are in Texas.  The gang has been worried about them and looked for them.  Dally gives Pony a letter from Soda.  He then takes the boys to Dairy Queen.

"Glory," Dallas said, amazed, watching us gulp the stuff down. "You don't need to make like every mouthful's your last. I got plenty of money. Take it easy, I don't want you gettin' sick on me. And I thought I was hungry!" (Ch. 5)

Dally tells them that the Socs and greasers are about to have an all-out war over the death of Bob, but Cherry does not blame them.  She knows that Bob was a mean drunk and started the fight because he did not like Cherry being with two greaser boys.  Dally calls her a spy for the greasers.  The boys hide at the abandoned church because they assume that no one will believe their side of the story.  It is good to know that Cherry, at least, is on their side.