I say sure it's better than nothing, although there's not too much technique-wise that you can gain from it. Things like bokken and jo katas can be practiced, along with rolls, rowing exercises, etc.
Personally, I've tried some different things, like throwing my jo into the air and then trying to blend with it as it comes back down(rather subtle differences between good n bad catches... the longer you wait, the more difficult... perhaps not the best solo idea, but it's somethin). Be creative I suppose...
Better than nothing, best in spirituality. Somewhat little to gain in regards to self-defense though it will help some.