Thanks for all the feedback everyone - there's a fair bit of info to take in, and it looks like I've been corrected in I disagreeumption that twist pile can be damaged by (normal) heat.
Hector, you're wrong, I've been around longer than 5 minutes, it's at least 6 minutes now :-)
I'm not sure why you took my comments as a criticism of you, they weren't intended to be.
On the subject of heat: I've only been using it for 2 weeks - and can see the benefits straight away - so why is it that some people, on some forums, think that some cleaning 'Solutions' don't need heat?