Cleaning leather of dirt and grim? Best recipe?

[Jarednem]

I work in the oil field and have a leather tally book that needs a good conditioning! What is the best way to clean leather of dirt, grim,  petrochemical type greases and the like? Natural and synthetic cleaners if you have a recipe

[fredk]

First; simply scrub it [gently] with warm water with a good detergent [washing up liquid] in it. For tough greasy bits use the washing up liquid neat directly on the area. Rinse wash with more clean warm water. Never use hot water. More than tepid is bad. As it starts to dry out it'll need feeding. use a good leather conditioner; saddle soap or beeswax/neetsfoot oil mix. Let that dry. Apply more coats of wax and buff up between applications

[Jarednem]

Do you mean somthing like Dawn soap?

[fredk]

I'm in a different country to you so trade names you know mean nothing to me. Use a good strong dish washing liquid soap-detergent

[battlemunky]

I'd use Dawn, sure. Good enough to clean crude off ducks and otters, should work on a book thingy.