Sheesh, there are some bad suggestions in this this thread, but the worst is ammonia. My, my the things you can learn on the internet.
You can’t do a good job weighing .1 grams on a scale good to .1 grams. But even the old non digital triple beams are good to .01 grams, and Big Girtha is right, there are relatively cheap ones at head shops.
I wouldn’t dissolve in liquid as you won’t know the degradation rate. Kitsnmore says their liquid cialis lasts 2 years at least, but they know the specific degradation for that chemical in that solvent.
Here are some easy things I would suggest.
1. Take your 1 gram pile and divide it into 20 small piles using your eye. Each pile is 50 mg and probably accurate by 30%, so they would all be 35 to 65 mg roughly. Not bad for no effort or expense.
Or, you can find a small coke spoon or cap of some sort that is the right size to more accurately measure out that 1/20th size pile.
2. Buy 100 grams of inert powder from a health food store, like maybe creatine, or inositol, and thoroughly mix it with your 10 grams of sildenafil. Then use your half teaspoon again. It doesn’t matter how many piles you get, you can calculate how much V is in each because you know all the piles add up to 110 grams and each pile is 9% V (10g/110g).
If you could get a scale, even for a day, you could get different sized capsules from a health food store, fill them, and then weigh the contents to see which size capsule gives you the dose you want. You would only have to do it once, you wouldn’t need to weigh every capsule.
Fortunately, I have a triple beam.