Lens Cleaning

I picked up an old Pentax K1000 for about nothing, hoping to use it's lens.
It looked as if someone tried to clean the lens and camera from sitting
around with no case or lens cap and smeared whatever was on it.

Gathering from the stench of cigarettes on some other things selling with
it, I'm guessing it's nicotine. I see no dust inside and the rear of the
lens looks great.

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Thanks.