what i do with tuna is put half the can in and blend it then add coke blend it then add the rest of the tuna with abit of more coke and blend it. remeber dont use too much coke. then at the end i pour it out into a jug and put in coke on top this allows me to drink the tuna in seconds instead of eating it in minutes (about 5 per can)
also you can use any fizzy drink.
all this does is add a bit of a fishy taste to it.
remember drain ALL the water/oil in the can before you do this or youll get some nasty shit.