I think the only way to safely speed it up is to shorten the trip the water has to make. Make the stave smaller/thinner.
Osage can act like a spoiled child when chasing a ring on a wet stave. I have had grain tear out with sharp drawknives and dull drawknives alike. Who needs the headache? Just quit several growthrings before final back and reduce the belly. Seal the back, and stand it in the corner.
Buy a cheapie digital kitchen scale, one that weighs in grams. Weigh your inch and a half wide by inch deep stave every week or so. Write the weight in pencil on the back to track your weight loss. When the stave really starts to slow down losing weight then move it to where the sun hits it during the day and air is moving (forced air, fan, or wind). Keep tracking every few days. When you are losing single digits daily, you can stick the stave in a hot car in a Phoenix parking lot if you want and it won't crack!
I pushed a green osage stave to dry in under 6 weeks and didn't suffer a single crack. It made a decent shooter, too. However, I asked for the bow back several months later because the tiller looked a little off. When I checked the draw weight, it came in another 4 lbs heavier and it needed to have the handle heated and bent to get the string back in line with the handle. It needed a touch up to the tiller and came back at the same draw weight as before.
If you start with slow drying your stave until it is losing only 10 grams a week, you could probably throw it in the dehydrator to finish making jerky out of it.