So this was bothering me like crazy. Especially since I was playing on a voltz server and needed the pink slimeball to make a laser drill setup. Luckly I figured it out! It's a bit of a workaround, but it works:
1) Run the Slaughterhouse without a pipe attatched
2) Right click the Slaughterhouse with a bucket when you get over 1000mB of liquid meat
3) Now attach a Liquid Router to the Slaughterhouse with a pipe
4) Drop the Meat Bucket you just aquired from step 2 into a colored slot of your choice in the Liquid Router. For this example I'll use Blue.
5) Attach a pipe from the Blue side of the Liquid Router to a Meat Packer. You can also put a chest next to the Meat Packer to get some initial raw meat.
6) Run the Slaughterhouse now and Liquid Meat will be routed to the Meat Packer.
7) At a certain point the internal tank of the Slaughterhouse will register some Pink Slime! At this point Liquid Meat will stop being routed. I guess the Pink Slime stops it from entering the internal tank.
8) Wait till the Slaughterhouses internal tank reaches 1000mB of Pink Slime.
9) Right click the Slaughterhouse with an empty bucket
Now you have a bucket of Pink Slime!
Tips:
What I did next is use the 2 Slime Embiggening Syringes on the Pink Slime after I right clicked the ground with ithe bucket of Pink Slime. This made it it's largest size. Then I chopped it down and got 3 medium Pink Slimes, then 6 Small Slimes. At which point I right clicked one with a Safari Net(reusable). Then finished the rest off for 5 pink slime balls. Now if you make a Auto-Spawner you can use the Safari Net to mass produce Pink Slimes and feed them into a Grinder! Mass Production
Hope this helps. A bit late, but maybe it can help someone else if you've moved on from voltz.
Edit: Also everything except the liquid router needs power. I found the Universal Cable to work with an Energy Cube, which inturn can be hooked to anything.
