Newspapers or magazines are good at absorbing odor. Failing that, remember that leather absorbs the odor of the last thing that was in it. So if you have just had a bath, put on cologne quite heavily and sit in the chair, it should absorb that but I have found that witch hazel works best. All you have to do is wet a piece of absorbent cotton (even a bath cloth if it is cotton) in witch hazel and wiped the chair with it. Don't wet the cloth much, just dampen it and repeat. Then use your regular leather treatment on it.