I have more dry hair and it doesnt grease easily so I havent test it by myself but it maybe tastes a little like salt but doesnt smell like it :)
You should normally wait 5-10 minutes after brushing the lash mixture onto your lashes. It doesnt need to dry, it´s just like oil in your hair. It will dry over night but if you apply a gentle amount you wont have any problems. Just dont put too much product on the lashes.
I'll try it! I go through mascara like no tomorrow, so I have a ton of near-empty bottles... can't be bothered to scrape all of it out.. I get impatient and grab a fresh bottle instead! Maybe this way, the near empty bottles don't have to go to waste!