If the OP is looking for a negative retouching dye, that should work. If the OP is looking for an infrared sensitizing dye for film, the crocein scarlet probably won't.
There are several cyanine derivatives that can be used. I don't have the link anymore, but somewhere in this emulsion making subforum, PE posted a page from an old Eastman Organic Chemicals list that had the common names and chemical names of some infrared sensitizers. A couple of these are being sold by Chemsavers (on the web) by their chemical names.
Happiness is a load of bulk chemicals, a handful of recipes, a brick of film and a box of paper. - desertrat
Looking for some for possible emulsion making, as well as re-sensitizing x-ray film to hopefully give it some infrared sensitivity. I have heard that this may be possible, so I'd like to give it a try. I too, am almost out of IR film.