I camped and killed it earlier this week, did the whole quest in a single evening. I saw the slime spawn twice within 2-3 hours without realm hopping at all. I missed the first as was briefly distracted but it spawned agin about an hour later. I posted a group on LFG too as it hadn't been pulled, of course one idiot joins and pulls it straight away so only one other Paladin managed to join and get a tag...
The fishing took me maybe 200-300 casts.
Gotta say though, some people are bloody awful at camping stuff, so many times I see multiple people completely miss stuff as they're afk. Got one of the hardest Kosumoth orbs (a cross realm one) within 5 mins on the first day it was figured out (when it was hard) because the other 6 or so people camping it were just chatting away. It spawned, I clicked it, and went on the the next, don't think they even realised it had spawned.