Thanks it worked! thought i only fund the item in the Slime Queen's castle, was the tf item removed from normal Slimes?
Random encounters who just happen to be slimes (and only want to mug/rape you instead of transform you) shouldn't carry canisters.
Some slimes you encounter in Submission are actively angling to transform you into a slime in their introduction text. When you defeat this type of slime, you can get a biojuice canister from the victory reward instead of a slime quencher, and you can open their inventory and take the canisters they are carrying too.
These are the sorts of slimes you need to run into to advance the slime queen quest, so you might still have one marked on your Submission map somewhere. They'll stay on the same tile if you don't chase them off or enslave them (you can't befriend them), which allows for endless rematches. As far as I've seen, they won't restock the canisters in their inventory that you took, but you can still try for the random victory canister over and over.
I
f you tell the queen to stop transforming random people, I think the slimes who want to transform people will stop spawning entirely. Or at least, they become absurdly rare; I've been unable to find one despite exploring Submission and the caves post-slime-queen-quest for a while. Edit: I finally got another one to spawn in Submission. While it's rare, at least it's still possible to get them to spawn after telling the queen to stop. Just savescum exploring/reloading the same tile over and over if you don't want to needlessly pass time in your game.
There are a few alternatives to using biojuice canisters:
If you decide you want to turn into a slime, you can return to the queen at any time, and take a slime bath. This turns you into a slime for free.
If you want a slime slave and have no biojuice canisters on hand, you can request slime TF as a distinct feature when ordering a custom slave from Helena (requires doing her questline to refurbish her shop in the slave district). It's a separate step after you pick their physical specs.
If you want a slime companion, I suppose you'll just have to befriend one that spawns as a slime. At least regular slimes are very common compared to the sort that want to transform you...