I think you mean a bunch of changelings and a Saliva....
But, the way out of the Saliva cave is through the right wall at the top end of that small room. It can be a death trap even for experienced players, but killing a saliva is required to get a key for Melisande. The way out of the Grove, if you've not been there before, is through the left wall on the ramp you entered on.
I hate it when people have changelings chase them to the door, and they jump you when you come in later.... It could have been worse, I suppose - sometimes people leave Tangle, Coil or Abscess at the entrance.
If you want to hunt Thrasher, I suggest you pick up the virtue of Honor, and train it as high as possible. That way you can honor yourself right before you go into the Blighted Grove, and not get jumped at the entrance if anything's there - then use the rest of the duration to find Thrasher, if someone's led him off from his usual bottom spot in the lower right, and kill him without interference, to get him respawning where he belongs (or to draw stuff that's wandered into his spawn area away from it).
Note that Thrasher also has a secondary money source in that it can be skinned for an obscene amount of normal leather; get a butcher's war cleaver (so that the carved leather goes straight to your backpack as cut leather - a skinning knife works this way too, but requires you having to equip the knife, while the BWC works while just sitting in your backpack) to speed this up - a harvester's blade is even better (+10% or more leather, working like the BWC), but it moves the ribs into your pack as well, that you constantly have to drop to maintain weight. Move the leather to the ground in a single pile, and send it to your bank with a Bag of Sending (which also works good for gold, if you've found out about this already). You'll be able to send about 400-500 leather or a pile of 60,000 gold, with each charge of the bag, from your backpack, without leaving the Grove.
As for your actual question:
Run by the three Ilshenar champ spawns. One is in the Valor region, west of the moongate, across the river, north of the brigand/evil mage ruins. One is East of Humility gate, in the jungle, near the lava vent. The last is in the Spirituality region, NE of the moongate. The last is a Lord Oaks spawn, the other two rotate between the other original types other than Oaks.
Depending on your template, you might need one to three other people to get the bosses to the bosses, and some bosses are more easily soloable than others. On most shards (all but Siege Perilous & Mugen) this is a non-PvP facet, so the only danger is the spawn itself (and other creatures not part of the spawn, such as the elementals, efreet and lich nearby at humility, and elder gazers, dragons, Greaters, drake and mummies that are in the area surrounding Valor, will sometimes be an issue - especially if paragon).
Most spawn during the last few candles have a decent amount of gold, and spawn fast. When the boss dies, it drops several hundred thousand gold onto the ground in 1k-6k around its death location. Many of the spawns also have creatures that have leather, gems or other valuables to take from the corpses.
If you do Oaks, you'll want to have a positive karma (when it gets too low, go farm miasma, thrasher or go to ice for ice fiends to get back up into the glorious range), and concentrate on killing only the wisp types and centaurs for the first 3 levels (no karma hit - on the other hand, the ki rins and unicorns give horned leather, but killing them makes you have to re-do your karma 10 times more often; centaurs give spined leather). On the 4th tier ignore ethereal warriors, and only kill the Serpentine dragons (safer than fighting the warriors, give scales and barbed leather, decent gold, and I think less of a karma hit - besides, the ethereals will rez you if you die - rez kill/you if you're negative karma at that point). both 4th tier monsters (and the bosses) cause karma loss, but are often done quickly enough that if you don't kill the masses of low-karma creatures (unis, ki-rin, pixie) you can get 5-10 times through the entire spawn without having to stop to get your karma back up, from a Glorious-level karma range.
You have to hit oaks enough to get Silvani spawn, then get away from Oaks, draw Silvani off far enough away to not be fighting her and Oaks at the same time, then kill her, before Oaks can actually be hurt. After she drops (and she has an empty corpse), kill Oaks.
This goes a bit quicker with two or more people, but I've seen it soloed (in fact, I've seen people solo all of the SE and eariler Ilshenar champs except Rikktor, but you got to be female to have a prayer against Semidar).
Making an acquaintance or two willing to share in the gold (and some don't even loot the gold on the ground) and help clear these spawns can be a really fun way into getting masses of gold directly, and from loot (since some of the items that can spawn on a champ corpse, or fall into your pack like an artifact drop, can be worth quite a bit when sold).
Another place people farm gold are Troglodytes/Lurg, but those are typically camped as often as Miasma is. Ice Fiends in Ice Dungeon are good, but the pauses in the spawn might have you going back and forth between the upstairs and downstairs spawn (the downstairs spawn are the only spawn downstairs, and is typically one at a time, with a random second one making an occasional appearance). The upstairs one is right around the corner from the White Wyrm, which is also popular for gold, barbed leather and gems.
For those not faint of heart, the Shadow Wyrms on Destard second level and the Balrons in Hythloth, Blood dungeon, Cyclopes dungeon (the other side of the wisp/evil mage dungeon) and in the path north of Chaos gate are also nice sources, with the danger of Paragon balrons from those three Ilshenar locations.
