Cleaning the washing machine

[MonkeyChicken]

Our washine machine is about 8 years old and we live in a very hard water area. It gets a lot of use (especially as I have real nappies). DC2 is due in about 9 weeks and getting the washing machine clean is on my to do list before baby arrives. I've bought washing machine cleaner stuff in the past which you pop in the draw. I occasional do a hot wash with bio powder and usually include a good slug of vingar with most washes. There's a thing I unscrew on the front of the machine that lets lots of water out which I do ever couple of weeks. Is there anything else I could do? Can you "get a man in" to clean your washing machine in the same way you can for your oven?

Thanks.

I use those Calgon type tablets in every wash but still occasionally have break downs caused by the hard water.
Last time I had the engineer out, he sold me some superstrength descaler which you use once a month.
Only problem is that it turns the scale to sludge so the first couple of washes after you use it there are grey smudges on the laundry
Not sure what the best solution is...