I never could get a nicot to work. tried everything
I tried the Nicot laying cage evey season for around 10 years - did something different every year - never got even the one larva to raise to a Queen Cell.
Then I went back to the method used in the original Patent - which specifies a plain shield (which neither Nicotplas nor Jenter supply - so I made my own) which covers the eggs so that the donor-colony bees can no longer access and destroy the eggs, which sometimes happens if they want those cells to store nectar in.
Then, after a couple of days, just prior to hatching, I placed the laying cage - without the protective shield - into a hopelessly queenless colony. By "hopelessly queenless" I mean a colony which had been queenless for well over a week, and so had probably forgotten what it's queen had smelt like
, and so would hopefully not destroy the eggs which still smelt of another queen.
BINGO - by late in Day 3 I was pulling cup after cup with ideally-sized larvae. After all those years of complete failure I would have settled for half a dozen, but instead got near enough the full 110. To tell the truth, I became somewhat bored with pulling successful larvae one after another, as there was no longer any surprises in store.
So - it may be worth trying a protective shield, and a hopelessly queenless colony.