Finasteride dissolved. All the other stuff did not. a cubic centimeter of water weighs 1 gram. A cubic inch of water weighs 16.4 grams. That proscar pill probably weights 200mg. a mg is 1/1000th of a gram. There is only 5 mg of finasteride in that pill. The other 195 mg is what you see undissolved. It is mostly starch and talc and other crap just so you can hold the pill in your hand and the finasteride won't be exposed to the elements as much and will last for years. If you don't grind it well enough (meaning there are little chuncks) than only the finasteride attached the the surface of the chucks will dissolve in the ethanol (you can use everclear, but 70% isopropyl alcohol is cheaper and should work as well and eveaporate slower.). So grind it good and maybe grind it some more after adding some drops of alcohol. This will also keep them from getting all over the place. Then add more alcohol and stir up the chunks good. Do this by putting the mess in an emtpy rogain bottle, adding rogaine, shaking good, and letting the chucks settle over an hour (since I doubt you have a filter, and I don't know if finasteride will have an affinity for the filter). Most of the finasteride should be in solution then. Once it is settled (kind of difficult to see in a non-clear bottle - maybe use a small clear container instead), carefully pour the liquid into another rogaine bottle and try to leave the chuncks behind. The chunks are not bad, but they can clog pores a little and interfer with finasteride absorption in your scalp.
Congratualations: the 5AR type II in your follicles will get first shot at the finasteride before you prostate gets it. Bad news: most of the 5AR in your scalp is skin is type I, which finasteride has little affect on. The type I will continue to make DHT which will diffuse over into the follicles anyway. That is why I'm getting dutasteride. However, this would happen anyway if you had swallowed the finasteride. And this way, your body gets a lower dose and will have less side effects.
Now the big question is, how much of the finasteride actually makes it through the skin, and how much is wasted on the surface, and is enough wasted to make this technique more expensive than just taking the pill? While I did some real speculation with Dutasteride, which looks like testosterone with an extra benzene ring on it and therefore may absorbe differently, I do know that finasteride looks almost exacly like testosterone (the similar shape is how it tricks 5AR to take it instead of testosterone, and then it gets stuck in the enzyme, shutting it down). I also know that 1/3 of high dose testosterone patches in a paste will make it through the skin. I also know that the lower the dose, the higher the percentage that makes it through. And the more liquidy the dose, the higher the percentage. So I think you will be just fine. And remember than about 60% of dutasteride is absorbed in the gut, and not all finasteride is absorbed in the gut either, so if some stays on your scalp, that is not a big difference from the oral route.
Use minoxidil if you can handle it, and use 70% isopropyl alcohol if you can handle. Use at least 1 pill per month, but use what you can handle without side effects. Some of the finasteride will make it to the blood stream and to your body, but you can adjust your dose as needed. I personally would use the 3-6 pills per month if I were going to do it.