this has been posted on that forum:
Its been a long time since anyone posted a reply, but google takes you here first if you have bluetack on carpets trouble.
I have the answer! And it couldn't be easier.
Just trickle some vegetable oil onto the bluetack and then scrape like mad with the edge of something hard until it magically vanishes. And it does! It takes seconds usually.
My carpets are dark, but if yours are light you may be left with a grease mark? But this may be washed out with carpet shampoo I think.
Anyway, the answer! And I worked it out myself
maybe doug could spread some light on this !?