Light is used in bath oil; the only use I know for heavy was my
grandmother taking a spoonful every night to keep her 'moving'.
I use mineral oil in the shop to lubricate moving jewelry parts that
stick. Usually it’s something that has come out of the sonic and
been steamed and it’s so clean that it sticks, like an omega earring
back or a clasp. Just a little dot ofmineral oil will lubricate it,
it’s nice because odorless and colorless.
Be warned that it can be a little embarrassing to buy. I remember
going to buy a bottle of mineral oil at a big, crowded pharmacy. I
asked the check-out person where they kept the mineral oil and she
shouted, “Hey Jimmy, isn’t the mineral oil with the LAXATIVES. Yeah,
with the laxatives in aisle seven!” I quietly said, that I’m using
it at work, but I’m sure that just confused things.