Have already done the research on using nicotine to worm ruminents.I did this many moons ago,though. BUT, big but here.....it is only effective against minor parasites, pins,rounds, not your major problem parasites such as brown stomach worm,barberpole worms,ect. Ground tobacco(cigs and skoal) are also not as effective as "leaf tobacco" (cotton boll twist,Levi Garrett,ect). There was also no known dose,so you are taking a chance of nicotine poisioning.
My suggestion....with the price of tobacco now days, stick to wormers that have been proven to work on minor & major parasites in ruminents.
Kaye