Hi Mathi, I hadn't occurred to me that Hobnobs might not be well known outside the UK, but of course, you're right.
18a I think are famous all over the world.
10a My problem is I've seen 2 spellings of this phrase (the penultimate letter is different in each) and the wordplay doesn't seem to lead to a particular one.
I always remember "Bic" because, many years ago, Private Eye had an article where they used the word "Bic" instead of "pen". Forward on a few weeks and Private Eye publish a letter they've received from the Company's lawyers telling them that "Bic" is a protected brand/trade name and they must never use it without permission from the company!!