If you press After Effects (the blue accordion bar)
http://revisionfx.com/products/twixtor/support/
You will find more
If you want to produce a 20X slowdown
Simply 1) drop your footage in comp1, set comp1 duration to a minute (1500 frames at 25 FPS)
2) drop comp1 into comp2 (new comp from comp so it is 1500 frames as well)
In Twixtor set Mode to Speed (it defaults to frame)
Set Speed to 0.05 %
Render
Pierre