Of course. That's how I tie all my flymphs -- and I tie a lot of flymphs.
Almost hate to admit, but what I like best about this method is that while I can't tie and watch TV at the same time, I can work the dubbing block and watch TV at the same time. I'll make up a bunch of bodies one night, and tie the next.
It's also easier to make multi colored bodies with the block -- lay down a light color at one end, and a darker at the other for a thorax. It's fun to experiment.