All, with regard to the subconjunctival injections - whether administered 'properly' under the thin conjunctival membrane covering the sclera(white part) of the eyeball - or 'incorrectly', as when folks just inject it into the eyelid - I think both are outdated (bordering on bogus) treatments, and that as soon as the medication injected stops leaking out of the needle be nice hole, it's no more effective than if you'd injected that 2 or 3 cc of stuff into the hindquarters of the animal. Far better, in my opinion, to give an appropriate dosage of a systemic antimicrobial that is known to reach therapeutic levels in the tear film... like oxytetracycline(LA-200/300) or Draxxin - that way, the eye is constantly bathed in a treatment-level dose of the drug for 2-3 days.
Anything you squirt in the eye (nitrofurazone powder, mastitis medication, WD-40(wince), salt, etc.)is going to be washed out within 20 minutes, just by normal tear production... probably even faster with the increased tearing that accompanies pinkeye. If you wouldn't put it in your own eye... don't put it in your cows'.
I'm still extremely skeptical about the Vetericyn products... looking at their MSDS sheets, they're really nothing more than a VERY dilute chlorine bleach solution in 'electrolyzed' water. Sure not worth $30 a quart(or is it $30/pint?), IMO. But, I guess they don't harm anything... other than your pocketbook.
Now, on to distrust of 'drug company vets'... I'm not sure what your (generic you) mindset is on this, but I believe it's misplaced. I've known and worked with - as a large animal practitioner, academician, and beef producer - a number of tech services and research veterinarians at Pfizer/Zoetis, Boehringer-Ingleheim, etc., for years, and have personal relationships with some going back 40+ years to our undergraduate study years. I have confidence in them - they're not just 'out to sell more of their own product'... they'll tell you, straight up, if their product doesn't work, or if another company's is better - their parent company may not like that, but all that I know are straight shooters.
Additionally, some of the most useful research that's been done in recent years, with regard to optimizing immune response in cattle, and minimizing adverse reactions/interactions between various vaccine components has come from the work of these 'drug company vets', many of whom have gone to the industry from academia - and now have the $$$ resources at their disposal to do important studies that are helpful to us in the livestock production sector that just don't happen at the universities, due to a host of issues, most relating back to funding.