I found this cream definitely effective, very economical and pleasant to use. If buying online from the Amazon site, compare the different resellers here, as their prices vary widely, and remember postage.
This product combines a 1-5% nonionic surfactant polymer with 1-5% isopropyl alcohol (a.k.a. propan-2-ol) in a creamy excipient base alongside a blend of synthetic aromatics to vaguely simulate the smell of leather. The manufacturer's website has a link to the product's safety sheet, revealing it may be mildly irritant so should be washed off exposed skin, but it's relatively innocuous in normal use. Using kitchen gloves is wise if you're going to apply it manually.
I acquired an ageing cream leather suite with a tired grubby look. Yesterday, I tested a spray leather cleaner against this cream product. The spray was frankly useless, but the Astonish cream, liberally hand smeared on all over and left for a minute or so, brought the leather up beautifully and removed signs of some mould and stains easily. It didn't, not surprisingly, clean every bit of the stain from the grain grooves, but it removed enough to make it very presentable and it smelt quite good too. I used a liberal 125ml from the bottle on my large sofa, so it was highly economical. I recommend it and will use it again. Testing it on a patch out of sight is a wise precaution, as it does lighten the colour a bit (at least, temporarily) and, if you apply it in squirts, will leave streaks of lightened colour, so is best applied evenly in one go, ideally by massaging it in wearing rubber gloves but you could apply it with a sponge. Don't apply in patches but cover large areas in one go, then rub off with a cloth and lightly buff. It doesn't need a lot of rubbing in, just applying, leaving a minute then removing, basically. A day later, the sofa looks cleaner, totally dried off and renewed and it really took very little effort or money to achieve this. Incidentally, it is not for use on suede, only shiny or hide finishes. It is available cheaply in many stores, so price comparison is recommended.