I know a lot of people aren't super enthused about the low chance of actually recruiting a Wild Wolf, so I had an idea that might be a good pebble sink: a consumable item (flavored however the devs want, the potion of charisma was just my first thought) that increases the chance of successfully recruiting your next WW by a certain percent. And if they still fail, they get more than one knucklebone token out of it so that it doesn't feel like a complete waste of the item.
My suggestion is for pebbles in the MM as that would both make them more accessible to new users and also act as a pebble sink.
I'm not personally attached to wild wolves specifically and haven't successfully gotten one yet (save the time my den was full... friend gave me a consolation WW for my heartbreak XD) but I know it's a bit of a divisive topic among users. I just figured this might be a nice compromise.