If the hole is back and he's bleeding, I wouldn't soak the area without speaking to the vet first. If it's not yet infected, that could cause an infection to start. If it's already infected, soaking can make it worse. You'll want to keep the area clean but soaking doesn't accomplish that.
I'd either get him to the vet right away, rather than sometime this week, or call the vet and ask what you can do for him in the meantime. I wouldn't want an infection and abscess to run rampant for several days untreated.