Were McCoy's medical instruments Swedish salt shakers?

Question

A rumour I had heard a long time ago was that Dr. McCoy's small medical devices in The Original Series were actually Swedish salt shakers.

Are there any statements corroborating this?

Answer 1

Yes, they were.

The following excerpt from an article quotes Gene Roddenberry himself (via the authoritative book The Making of Star Trek) as saying:

[Feinberg] went out and bought a selection of very exotic-looking salt shakers. It was not until after he brought them in and showed them to me that I realized they were so beautifully shaped and futuristic that the audience would never recognize them as salt shakers. I would either have to use 20th Century salt shakers or I would have to have a character say “See, this is a salt shaker.” So I told Irving to go down to the studio commissary and bring me several of their salt shakers, and as he turned to go, I said “However, those eight devices you have there will become Dr. McCoy’s operating instruments.” For two years now, the majority of McCoy’s instruments in Sick Bay have been a selection of exotic salt shakers, and we know they work, because we’ve seen them work. Not only has he saved many a life with them but it’s helped keep our prop budget costs low...

(Source)

The author of the article, having done more research, concludes that Roddenberry's recollection was "slightly off" and that exactly two of the instruments were salt shakers while the rest were constructed by the prop team to resemble those two.

Finally, William Shatner himself mentions that the salt shakers were of Swedish origin in his 2002 book Star Trek: I'm Working on That:

...or how Bones was supposed to perform medical magic by waving weird gadgets (Swedish salt shakers actually) over damaged bodies.

(Source)

Answer 2

The Swedish salt shakers used – from what I've seen online – had orange and green wooden lower bodies and conical metal upper parts.