The split boot might make a good temporary fix to get fresh lube in there and to keep it in and the dirt and grime out. That is if you are doing it yourself, it will limit the time you are outside.
But a traditional boot is the best repair, and will require practically removing the axle if not doing so completely for ease of working on it.
And if you are paying a shop, you might as well just pay once and have the boot or complete axle replaced.
TB