Well, they don't say it's a wet process... so it should work with an intermediate drying step which should prevent the negatives from getting too cruddy. Though they say to put the base and ink together and not the emulsion side...
When you read the comments, one of the Inkodye people suggests to put some Saran Wrap between the negative and the inked fabric. That's the safest thing to do.
What fascinates me is that what fixes the dye is actually the washing step which physically removes the product from certain spots... not unlike cyanotypes and many other alt. processes.
Somehow, the product feels a bit like "back to the future"...