I have one of those that my Dad gave me.
He had it as a toy in his youth.
The "oxidizer" was powdered Alum which when dissolved in water is an acid that reacts with the "fuel" Baking Soda to produce the CO2 that pressurizes & launches the rocket.
I can tell you from trying it out, it flies DISMALLY low (under 75') and makes a mess on the lawn.
A decent toy store water-rocket will fly higher.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !