graybeard's advice is excellent. We've used the rubs for several years with good results. In our experience, they need to be strategically placed so the cattle have no option but to accept and become acquainted with them. Its also a bit of a trick to hang them so the cattle can't duct under them. A generous length of poly or nylon rope added to each end allows for adjustment tweaking.
A couple of additional suggestions regarding initially charging new rubs: Initial saturation is bit of a challenge. I tried the sprayer method and was frustrated by both the time it took to fully saturate the rub plus even sans the sprayer nozzle head it tended to splatter rather than penetrate. To solve the problem I use an empty lick tub dedicated to the purpose. New (dry) rubs are a stiff and unwieldy. I place one end in the tub and then carefully coil and stack it upon itself and then slowly pour the insecticide mix over it and let it sit for at least 24 hours, tipping the tub numerous times to ensure the rub is completely saturated. If you started with 2 gallons, its likely not all of it will be absorbed. I pour what's left back into my storage containers. Speaking of which, I repurpose several clear or semi opaque plastic ones capable of holding at least 3 gallons and preferably, have incremental gallon indicators, i.e. empty Cydectin pour on jugs, etc. Fill with the appropriate amount of diesel, funnel in the insecticide, swoosh it around and you're go to go.