this has to be a joke. i don't see how one could look into the term 'mainlining' and come up with what you've written here.
anyways...in humans, nutrients circulate throughout the body using the blood stream. that is how our vascular system works. in plants, the vascular system is comprised of two main types of tissue: xylem, and phloem.
please post what you read that led you to this idea. as you can see above, this method is not meant to make a plant produce more flowers or grow bigger. i can't find anything where people have injected the stalks of their plants with the intention of increasing that plant's production.
not to mention your title and the way you worded this thread is an absolute joke. you did not research the term mainlining and come to the conclusion that this is what people mean when they use that term. you are quite obviously lying, just like you're lying about pulling 23 ounces off an autoflowering plant with a 600w hps. that's 1.2 gpw...anyone could look at the questions you ask in your posts and the threads you make and know you ain't getting anywhere near 1.2 gpw off an autoflowering plant...