Relieve fuel pressure before removing injectors?

While I've not done this work before, I've not heard of the need for relieving the pressure. I'd like to see the results of undoing them without relieving pressure because I've not seen anyone complain about it being an issue and you could help confirm that.

 

I usually just take the electrical connectors off all the injectors and (while the car is all turned off, of course) tickle one of the injectors with leads from a 9V battery. It squirts into the intake, relieving the pressure.

By the time whatever work I'm preparing to do is complete, that small amount of fuel will have evaporated and wafted around, and won't cause a flooding issue by the time I want to start the engine again.

I used the "run without fuel pump" approach once, but of course it causes heavy misfiring on the way to finally stalling out, and because any serious misfiring in a Prius will bang the daylights out of the transmission and input shaft damper, it sounds pretty horrible and doesn't make me want to do it again.

 

Thanks, I've edited my post to clarify that I have the car turned off for all work involving injectors, so the fuel pump will not have power.

I also never restart an engine, after putting injectors back in, without doing a fuel leak test first, by making the car only IG ON (not READY) and using a scan tool active test to spin the fuel pump while watching all the injector connections for leaks.