i've inherited my nana's suite and it seems to have a bit of a grey tinge to it. i know some parts are just wear and i wont be able to get rid of it but i should be able to brighten up the rest shouldn't I? so far i've only been wiping it down with a damp cloth but it really needs a proper wash and hopefully get back to the original colour. do i have to buy proper leather cleaner or can i use something else?