This is great
https://www.cleanyourcar.co.uk/zymol-leather-cleaner
for bmw leather steering wheels gets them grime/skin oil free and back to the soft matte finish in no time just give the wheel a once over with a warm water damp microfibre cloth then rinse and ring out the cloth spray some leather cleaner on and work it round the wheel rinse and wring cloth out again then wipe excess leather cleaner/suds off the wheel. Buff dry with a fresh dry microfibre and that's it back to as