For applying Hoof oil / Hoof flex on your horses hooves, you'll find a small sponge works just as well as an oil brush.
Old Horse Fly Masks make great wound covers and keep the flies off your horses' legs while still allowing the air to circulate to heal the wound.
Having trouble keeping your stainless steel horse bits and stirrups clean and shiny? You can soak any stainless tack item in a bowl of vinegar for several days to dissolve the rust. Rinse thoroughly after using.