Capture for creature blood

[Khalani]

So I was thinking, how can I get 100% creature blood potions, since you can't charm creatures like humans. Then I had an idea:

Why not search for a werewolf that has 100%, wait for the day, capture the human form of him and put him in prison.
So far so good, farmed for like 3 hours but finally got my 100% boy. The only problem is, as soon as it turns night again and that dude got into his werewolf form again, he simply escaped from prison and wasn't even an 100% werewolf anymore.
Don't do the same mistake as I did, it's a waste of time :(