Denise, I've used pinacyanol for photopolymers and AgX emulsions. With regards to AgX, most of my attempts related to Jeff Blyth's diffusion method. That's to say, I hardly did any sulfur/gold sensitization. Instead, I heavily relied on ascorbate reduction sensitization. I don't know what the situation looks like for more sophisticated photographic emulsions, but with crude red-sensitive holographic emulsions the combination of pinacyanol and ascorbate resulted in surprisingly good photo speed.
Originally Posted by dwross
To come back to gold sensitization) Wolfgang Baier, Die Geschichte der Fotografie, mentions the work of Dr. F. Kropff, who was said to have done research on gold sensitization for Gevaert in the mid 1920s...