Answer
Yes. You will be able to fill-in and wipe-away any space that you leave blank. The "Dry-Erase" feature is created by placing a dry-erase overlaminate onto the check material, so that the entire surface becomes erasable and reusable. Keep in mind — anything that is actually printed on the check is permanent.
When designing a dry-erase check, anything you do not want printed, including default text, should be completely removed from the design.