I've never seen the point of drying out frozen baits unless I intend on crumbing a batch up for a stick mix.
What I would suggest,is use the liquid food that you can sometimes get with certain companies.
For example, I used to dry out a kilo of activ8 boilies, then crumb, then start soaking in the activator liquid, not the enhancement system but the actual liquid food they supply for making your own.
As I've mentioned before, and yes this is a bit of a double edged sword subject, I wouldn't rehydrate with oil, the oil will just seal the bait, on the other hand, carp are attracted to lipids, so it's up to you what you want, but I'd be rehydrating with food.