I would spray it with the Z9 or a similiar product and let it sit for a minute or two and then it should come right off. The leather on the Z seats is coated and there is no reason something like that should stain it. You will love the Zaino Z9 and Z10 anyway. It smells just like leather. I even use it in my house on my Leather Couch, it makes my entire house smell great. It is also loaded with a lot of great leather preservatives that are really good for your seats and will protect them from future incidents.
I tried a bunch of different leather products like Lexol, Adams, Meguiars and even quite a few they sell strictly for furniture and none of them compared to Zaino IMHO.

I do love Leatherique for deep conditioning. I usually use Leatherique twice a year and Zaino Z9 and Z10 monthly. I just use Z9 and Z10 on my couch. I would go broke trying to coat my entire couch with Leatherique.