Madonna wants a ''soft butt''.

The 59-year-old singer is a big fan of the clay mask from her own MDNA Skin line - which has just launched in the US after previously only being available in Japan - and urged people to get their partners involved in slathering the cream on their backsides.

She said: ''I have used the clay mask on my butt.

''Don't you want soft skin on your butt? I mean don't a lot of people look at your butt? Your butt has an audience. At least one!

''Maybe you can ask your significant other to remove it for you. What do you think? You have it put it on and you lay down and he can rub your feet or she while your mask is setting in for 7-10 minutes, and then you can get some magnetic head on your behind.''

The 'Material Girl' singer - who raises six children - has always known the importance of looking after her skin, and when she didn't have much money, would visit a local ''heroin addict'' for ''amazing'' facials.

Speaking to a group of journalists in New York City, she recalled: ''I remember when I lived on the Lower East Side and I really didn't have much cash and there was a salon on 7th street between first and second avenue and there was a girl in the back -- and I know this is weird -- but she was a heroin addict, and she gave amazing facials and I would go to her and we would somehow do trades.

''Skin was very important to me, and I always took care of my skin, even at a young age.''

The 'Vogue' hitmaker also poked fun at her beauty style evolution over the years.

She quipped: ''There were many years where I wasn't interested in having eyebrows.

''There were many years where I wasn't interested in wearing bows. But my skin was always exposed so even in my sex book, I didn't have a real tan -- I had François Nars painting on a tan everywhere.''