I'd like to replace it but can't afford it just yet, and when we do replace it, I'd like to pass it on to a local charity so I need to get it decent condition. I've tried leather wipes and didn't really get anywhere.
Saddle soap smells nice and lasts a very long time, it contains glycerine, but you can also use a plain white or transparent toilet soap and lather it up well on a sponge, polish off with a clean (white) soft cloth.
Yes, saddle soap is basically just another soap, quite hard, with its own smell. It is slightly oily to "feed" the leather, but toilet soap is usually "superfatted" to moisturise the skin as it tends to wash away oil and grease. Try one that is unscented.