Yes, your sentence is perfectly correct. We need the "of" after "hardly any" when we are speaking about a specific sub-set of a larger set. So we can say, "Hardly any Americans speak Portuguese," because we're referring to a large group (all Americans). However, we would say, "Hardly any of the American engineers who are being sent to the Brazil power plant speak Portuguese" because we're now looking at a very particular and smaller group.

emarbe: When I reach such difficulties, I simply find an entirely different way of phrasing my sentence. You can write your sentence that way, but there are simpler ways of phrasing this idea with intelligence. Example: "Hardly any scientists admitted to experimenting on animals." "Few scientists admitted to experimenting on animals." "Almost no scientists admitted to...etc." "There is seldom an admission on the part of scientists regarding animal experimentation." "There are strong suggestions that some scientists at least, have opted for animal experimentation."