Try to get the Jack bomb as many as you can and throw it to the water, i was able to get just 1 salmon after 20 bombs, yeah the rng is pretty insane....
hmmm probably it's going to work but i just use the gacha machine and giving it some junk so that it will spawn a bunch of Jack bomb towards the water/river, so why not try that and that bunny ear it's probably going to work tremendously.