Keep in mind...
...that your tongue is "operated" by quite a few muscles that are called upon to do things when playing any musical instrument that they do not do during normal speech. In effect, the type of tonguing "exercise" given above is an actual "physical" exercise as well. Repetition of the boring path that Steve has laid out may not be fun, but it will expose those muscles to motions to which they may not be accustomed, and with the repetition comes the mastery not only of the mental side of clarinet playing, but of the physical as well.
When learning how to play the clarinet, there's quite a bit of physical stuff that you need to deal with to the point that you can execute it without thinking. Fingers on keys don't need to develop 'muscle memory' (no such thing exists - the skills lie entirely in your brain), but they do need to be able to execute the motions that your brain sends to them.
I've had long periods during my life where I've not put my hands on an instrument. When I did get around to playing again, it was a matter of "the spirit was willing, but the flesh was weak" as I knew exactly what to do, but my embouchure and hands were just not capable of making it happen at that remove.
That's where practice is essential, as it keeps both mind and body "sharp". And, when first you try to play, it's frustrating to the extreme.
Just keep at it, and the skills will come. And, don't ever pick up an alto clarinet - ask to play the bass instead.