I just use cooked shrimp cocktail to tip my jigs..one big/jumbo shrimp cut into 3 or 4 smaller pieces. When I'm fishing in faster water for steelhead, and because it's cold, I sometimes use spider thread to tie on chunk. It never falls off.
I've caught chum, steelhead and coho with the cooked shrimp (though coho seem to prefer sparse jigs with no prawn as others have mentioned). Raw shrimp has worked too, and I did experiment with pautzke's fire cure in bag with shrimp, but it stank, was messy and I didn't get a sniff that day steelheading. In the end, I like cooked shrimp the best because it's the cleanest and has caught me the most fish.
I personally think it works better than raw shrimp, but it may be because I use cooked more often.
I know Rod Toth of Bent Rods only uses raw and Cody at SeaRun likes the firecure in baggy with raw shrimp chunks, and both are excellent fisherman who catch a lot more fish than I do .. but my personal experience/experimentation yields greater success with cooked prawns.
YMMV.
Though, in the end when chum are on the bite I don't bother and just get my line in as fast as I can. And with steelheading, speaking from my limited experience, it seems to me what others have said often is true: you just have to find them, and it doesn't matter what you use, just present it them half decently.
I'm not sure how much it matters to tip or not. It just makes me feel more optimistic..