the cleaning stuff your after is called Ardrox (I have some Rick if you need any), the heat does help break the crap down and it doesn't matter if you use tap water in these providing you are not in a hard water area.

I'm always sceptical until I see if the thing does what it says on the tin....
So on YouTube and found this video
http://www.youtube.com/watch?v=wOlcxZrdCTQ
and that one
http://www.youtube.com/watch?v=xhGyK6MpkOQ

so... you guess it I bought this one now
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 338wt_1140
and @£26.95 ...