Yes, I had to wrap the whole hoof. I used an epsom salt/poultice combo product. I find it works far better then ichthammol (and it smells nice too). Epsom Salt Poultice (Equine - Health Care - Liniments)
Then put gauze over the ointment, vet wrap, duct tape. The horse I was treating ended up being locked up for a while. If you are going to keep your horse turned out, I would suggest putting a boot over the hoof so the wrap stays. The only problem with that, is it can rub the spot where the abscess blew out. (That is why the horse I was treating ended up staying in). It did take a number of weeks for it to heal. I'm sorry I can't remember exactly how many. She was sound when she was trying to schluff off her heal tho, which I found to be amazing for this horse. This is not a quick healing spot, sorry to say.