Carpet tape is good, I leave a gap the same width as the tape width between each "stripe" of tape.
WD40 is good for making it unstick. Use a wedge and gentle but steady pressure to separate the bits. Acetone is no good- just smears the sticky stuff all over your component as does Methanol.
Oh, if you're using coolant make sure it dun attack your sticky stuff otherwise body armour may be adviseable as your part lauches itself at 3000 RPM inevetably towards your delicate bits!
Personaly I'd double tape it to just an aluminium sacrificial plate and clamp this to the machine using standard clamps... not too sure how sticky tape would adhere to MDF. Also... coolant would make MDF swell up surely?
I love deadlines- I like the whooshing sound they make as they fly by.