Flutter Tongue

I believe you mentioned along the way that your tendency is to use the on/off flutter tongue and that most players tend to gravitate towards that or the side flutter type. My tendency is towards the side flutter but I'm working on the on/off as I figure the tongue is a muscle that needs a variety of exercise if it's going to reach its potential. To that end I've developed a simple practice routine and was hoping for your comment.

Because I find the on/off a bit unnatural I'm doing it very slowly. I first slap the note to get a clear single note then slowly add and remove the tongue to get a chordal effect then finish off with the last time I add the tongue to produce a single note again. Over time speed should increase.

Does that sound like something you might recommend? Thanks!