If going to 'big guns', I'd only use it on seedy which is not into live tissue. I would be very hesitant to use heavy chems on the frog. Aside from that, thrush & seedy toe, aka WLD, is essentially the same beast(well, beasts), just infecting different parts of the hoof. It can be bacterial, fungal or otherwise, or a combo, is an 'opportunistic' infection which means that it invades tissue that is unhealthy - strong hooves aren't really susceptible even in a paddock full of bugs. So topical treatments need to be broad spectrum antiseptics & a 'holistic' approach is best if a horse is 'prone' to seedy. Hoof balance/good regular hoofcare is part of that, as is a farrier who can safely 'resect' or cut out the infected hoof wall, because infection inside the wall is virtually impossible to treat if only topical.
So... of your mixes, I'd ditch the vaseline to start with, as you don't want to 'plug it up' or seal it(so also avoid hoof oils) - the bugs are almost invariably anaerobic, so the more oxygen the better to treat. That's why peroxide is helpful. I often use a '2 step' treatment, in which 6% peroxide is the 'part A'. Peroxide doesn't stay active for long though, like iodine & such, so I follow it up with something like tea-tree oil. As you're in Oz, there is a really good product for seedy, called Black Healer, available at Mayfield Barehoof Care Centre Home Page
& some feed stores & such. I'd stick to tea tree oil on the frogs tho. Manuka honey is also good for central sulcus thrush.