Spraying your buds during flower

Aside from pests, is there every a situation where you ever have to spray your flowers? Advanced nutrients has a rip off product called bud factor x which appears to simply be an overpriced magnesium supplement.

The interesting thing is they suggest using this product as a foliar spray in weeks 1-6 spraying directly spraying the mix onto your flowers which I always thought was a general bad idea:

+ WHAT THE BEST WAY TO GET MORE POTENT CROPS USING BUD FACTOR X AS A FOLIAR SPRAY?
Follow the label instructions and then spray Bud Factor X directly onto buds just before lights go off so it will have time to absorb overnight. You could also apply it about 20 minutes before lights go on. You want it to have time to sink in rather than be evaporated. Try for a pH of about 5.8 and closely monitor your buds to make sure you aren't overloading them. Avoid spraying buds in high humidity or when you are within 3 weeks of harvest.
http://www.advancednutrients.com/hydroponics/products/bud_factor_x/bud_factor_x_faq_nutrient_facts.php

So what's the general consensus here? Is it really a good idea to directly deliver magnesium to the bud sites?

On a side note regarding advanced nutrients:
I found their marketing rather amusing throughout my recent browsing of their products. They generically, repetitively, and emphatically tell you how each product is going to generate more bud sites, more resin, and a larger yield while never explaining the true mode of action of the product they're trying to sell you. Instead of explaining how magnesium is important in plant growth, they promise you more buds, more resin, and a bigger harvest....I guess people that don't know better keeps 'em in business, but I myself, was amused

im torn on this. i won't foliar after week 1-2 in flower as soon as they start forming at the moment but I'm about to have 2 4x4 tents of the same strain the same age side by side for the first time in a long time. this is one of the variables I've been deciding between to test, one of the front runners for sure too

i can only test one for it to be a true test and its between foliar in flower, aero sprayer top feed vs open 1/4 inch hose (testing air intake), and nutrient brands Rock vs Ionic

depending on how this thread turns out il have to figure it out in the next couple weeks. anyone ran top feed drain to waste hydro 180 degree sprayers vs open hose? open hose doesn't ever get clogged and is way easier to maintain but i feel like the air just won't be there for me?

Just worry about keeping your roots and leaves happy, they will take care of producing big oily flowers....

if you do, spray in the AM, buds will mold if still moist at sunset/lightsout. my 2 cents, learned the hard way.

When I lived out west, where the humidity dropped sometimes I would mist with distilled water a day or two before harvest. Here in Michigan mold is such a risk I have not. So no. There is nothing I would spray on a bud.

im doing a preventive foliar spray. day 10 after flip and day 21 after flip. might have a potential light leak hermie, so hitting them with optic foliar Switch.

One thing you will want to look at is, does the label say whats in it? if it doesn't I wouldn't spray the flowers. I know most companies don't show the ingredient list because they want to keep it a secret but thats no excuse when people are using it to make smokable medicine. Im going to throw an example at you gravity was pulled off the shelf because of carcinogens. people were using this for years and had no idea.