Sydney made it safely through Dr. Tolley's Numotizine wrap.
It took a fair amount and scrubbing and hosing, but I was able to rinse the Numotizine out of every crevice of Sydney's hoof. His foot looked really clean with no "gooey" spots. I even scrubbed the hole with a fingernail brush without any reaction from Sydney.
I soaked some 4x4 gauze pads with Iodine and packed them around the hole. I rewrapped the hoof with brown gauze and topped that layer with vet wrap. I gently wedged Sydney's foot into an Easyboot and then wrapped the boot with Gorilla Tape (a heavier duty version of duct tape).
I just need to do this one more time and then we should be ready for a shoe later this week.