Pure and Impure Items

Q: Do hair and nails become impure once removed from the body?

Q:

1. I don't know if this is going to the extremes, but is it permissible to take an ear medication (through the ear) that contains glycerin which may or may not come from animal fat?

2. If that's the case, would that make soaps also impermissible?

Q: Is it permissible to use aagarbattie that contains cow dung?

Q: Is it halaal to own leather products like wallet/phone pouch made from crocodile/alligator/snake skin?

Q: I am from India. Mufti sahab please let me know that can I use liquid stiffener (revive) in our clothes for praying namaz?

Q: Is it haraam to wear pigskin?

Q: If the fat from pigs is chemically processed so as to produce two compounds, both different from the original fat, it would be considered as istihalah?

Q: What is istihaalah? Especialy regarding products from pig?