While that might work to trap gold flecks, they certainly wouldn't stay there when you picked it up or shook it.
Even if I'm really, really careful?
Why would I shake it if I put it there for the express purpose of collecting gold?
Miners do nutty stuff to collect the smallest amount of that mineral.
Lanolin?
I'm not so sure. With a vigorous shaking you could undoubtably shake it free. But I think within a range of delicate it would stay stuck.