This is the product we used:
http://fromfinland.fi/en/havu-pine-soap.html
Don't know any other names or brands for this product, but there likely is some.
The most important thing was to wash the surface and vacuum the washing solution off while the surface was still wet. Pine soap doesn't dissolve silicone, but it removes it from the surface quite well, so you still have to remove the soap-silicone mixture from the surface because if you fail to do so, the solution just drys up and the silicone remains on the surface.
Just a reminder here is the video again where you can see what was the process we used for cleaning.
http://www.youtube.com/watch?v=7bvuR...ature=youtu.be
This doesn't clean the track 100% - but at least 85% so you should be able to race on the surface again, so the last bits of the silicone are removed by the rubber tires scrubbing the track.
BR,
Tuomas