Revving the engine up (for less than a minute) to where its making almost peak torque, to COOL the motor puts WY less strain on it. There's no load, and lots more coolant flow to cool the motor. Over heating puts more strain and wear on all the bearings than anything else. You'd be doing your engine a favor. I'm trying to help diagnose/fix your issue. I would never te you to do anything that's going to harm your car or make any other issues worse.
Do what you said and let us know how it goes.
Hose insulation is a waste of money.