I think my inexperience with toms is making me overthink this ...

We all have a tendency to do that so join the crowd. ;)

I'm surprised that the product doesn't come with good directions for use and it should tell you if water mixing is possible. What brand did you buy? Most of the dust forms of products are meant to be applied with one of the many dusting tools available on the market - applicators that disperse it in a uniform cloud that covers all parts of the plant - and range in cost from $5 to $50. But some also come in a "shaker" can with sprinkling holes in the top. I take it yours is not one of these?

Over the years I have found that you can get a fairly good application out of an old flour sifter or even an old salt shaker - the big ones you used to see around at yard sales. ;)

I don't have any personal experience with mixing it with water but the Bonide brand of BT page gives some info that might help.

Never heard of adding aspirin for any reason so can't help you with that part.

digdirt -- Thanks for the link, it was just what I was looking for! The bag that I got didn't have any instructions on it, other than to dust. Perhaps it was because I got it from a farmer's supply store and their usual customers are much more knowledgeable? But anyway, the website you directed me to was very helpful and I'll mix it with water. Lets see if that works. As for aspirin, I read about it in the tomato forum last year and was intrigued by the whole idea. Happy growing toms :)