Is there a particular difficulty you need to be playing on to find it, because I was playing the easy mode and I NEVER saw one of those things at any point
For now, you can only find it in level 0, and yes, it spawns on all difficulties. It usually spawns in the corners.
You have to click on it with the lube bottle, and a very quiet noise plays (fixed in the next update), which means it's filled up.
After that, you just have to bring it to the merchant stand and put it in the highlighted green zone.