Im planning on acetone washing some amphetamine sulfate, however I couldn't find anydrous acetone, so I resorted to make my own. I've done my research, however I have some problems.

I need to store the anydrous magnesium sulfate until I use it (about 1/2 weeks in between). Either that, or I will have to either make the acetone anydrous (which wont be used to wash the amphetamine sulfate for about 1/2 weeks) the same day I will be drying the magnesium sulfate, or dihydrate the magnesium sulfate in a microwave, make the acetone anydrous and wash the amphetamine all in the same day.

So what is better:

Dihydrate the magnesium sulfate and store it in a glass jar for about 1/2 weeks.

Make the acetone anydrous and store it in a glass jar for about 1/2 weeks.

Dihydrate the magnesium sulfate in the microwave as opposed to an oven and to all the rest in the sane day. Also how could I dihydrate it on a microwave?