Macey,
If you have much scabbing, it could mean that the electrologist is using overly aggressive settings on the machine. Then again, it might be that we're all different and some skin reacts more readily. I've seldom (as in only twice, in a couple tiny spots) had anything that one might call "scabbing", more like just some minor drainage that dries rather crusty. Swelling is another matter. I've had what looks like a big welt, over the treated area, last for two or three days.
As for length, I need three days growth to enable my electrologist to work quickly, and quicker is always better - more dead follicles per visit. YMMV.