On Monday, December 3, 2018 at 3:07:15 PM UTC-5, The Real Bev wrote:
The website guy used paper; what if I'd used a tiny bit of
toothpick sliver or wire or plastic?

Paper (or very thin cardboard) will absorb oils and grease - with special reference to skin oils. A toothpick is to coarse, and silver, wire or plastic will not.

A common practice is to clean out variable capacitors with business cards - for just that reason.

Peter Wieck
Melrose Park, PA