As for the so-called "intricacies of this particular Flor-i-duh technique" ... well ... it's all rather simple.
If ya have the traditional ketchup bottle, ya jest pound away until it comes pouring out ...

If ya have a squeeze bottle ... well ... y'all know how that works ...

Now, dependin' on how big she is ... ya may need to bring an industrial sized ketchup bottle, don'tcha know ...

BUT, I really don't know why his girlfriend is squawkin' so much ... he jest poured some ketchup on her ... it could've been worse for her ... some women prefer to be slathered with hot sauce!

The essential American soul is hard, isolate, stoic, and a killer. It has never yet melted. ~ D.H. Lawrence