No. Do use a pen or any other writing utensil. If you want to go this route, I suppose you could use a VERY well-cleaned screwdriver, large nail, awl, etc.,...
Use only one or two drops, depending on how much hot chocolate you're making. Vanilla extract is stronger than some might think, so don't use too much of it.
Fill a glass bottle halfway with fresh, clean lemon zest. Then, fill the other half of the bottle with olive, jojoba, or argan oil. Keep it under the sun for...
Sounds like you might just puree up some mangoes with a little sugar. I would recommend making it only in small batches, because the lemon juice is what keeps it...