Why these are ridiculous
Systemic sprays (like Grazers which someone imports from the UK) are designed to be absorbed by the target plant...so for systemic repellents the idea is that the plant will be sufficiently saturated with the repellent that when eaten its taste will do its work. Well that's a load of bollocks!
Firstly, the animal has to bite and chew the plant to get a taste, but by then it's too late as the plant will be stuffed, especially if they ring-bark or munch the young shoots and juicy growth points.
Secondly, the chemicals used (ie: calcium chloride) would have to be present in such a massive concentration in the plant that it would die. So in reality the concentration is so weak that it's undetectable by the browser.
Thirdly, the only type of repellent worth looking at is one that repels through odour and/or visual signals which would then stop the browser from biting and damaging the plant in the first place. If it smells decaying fat and/or oxidising protein that then triggers a flight response as it suggests a predator has killed something close-by. Basically, herbivore browsers will not tolerate dead animal bits or smells! Topical repellents are the better solution. If your dinner smelled rotten you wouldn't eat it would you?
BANGBANG is decaying animal protein so it gives off a sulphurous smell as it oxidises. The fat in FATBANG and GREASEBANG also omits an offensive odour plus the sight and texture of the fat does the rest. Systemic sprays are absurd and do nothing except rip people off!