in short, yes, they are worth it. I have small jewellers size one. I put items inside plastic cups (with warm water and dish soap in) in the water bath and clean things like jockey wheels, bearings etc. so much easier than hitting them with a toothbrush and brake cleaner.
the plastic cups keep the cleaner clean without needing to clean out all the oilly gunk.
it might take longer to clean, but it's non intrusive time, i.e. you are off doing something else while works it's magic.