Super dirty Natuzzi light brown leather sofa

[wole]

Hi folks!

I've just come into possession of a pair of super dirty 3 seater Natuzzi leather sofas. I believe that they are the "protecta" variety (as i understand it there are two finishes for these couches, natural and protecta, the latter being some kind of protective coating.)

This is one of the seats: https://i.imgur.com/DW2iEqH.jpg also first image below. I can only imagine that they came from a garage, so much grease and muck

So i tried laying a paper towel soaked in mild dish soap on one cushion for an hour, it's worked to a certain extent, but I'm wondering if there is a better way and what the best approach is to restore these sofas?
https://i.imgur.com/jf98XKf.jpg

Thanks for looking!