Or more specifically, is there anything much wrong with the Barbieri one? It's on offer from an OBS, at about 1/2 the price of the other ones, and I'm wondering whether that's because it's not so good, or just a clearance issue. I know the job can be done with a toothbrush, but I'm really after some help on this - has anyone had any experience with the Barbieri chain bath, positive or negative?

My first chain cleaner was a clone of the Barbieri and worked ok but
the Park is a lot nicer. Barbiere nominally has that wire loop on
back to retain it in place by hooking over the bottom of the RD
cage, but requires the bike to be suspended so the chain can be
moved in the forward direction. If you can't suspend the bike,
the chain must be run in reverse, and the Barbieri has to be
hand held in place. The Park recognizes this and gives you a
handle to hold the cleaner with. I think the brushes on the
Park are a little more aggressive in cleaning and seem to have
lasted a lot longer than the Barbieri clone I started with, the
Barbieri brushes looked motheaten after a few years. Park
also holds more cleaner - I prefer straight citrus for its aggressive
degreasing action. Yeah there is a big cost diff but in my book it
is worth it.

I have the Park chain cleaner also. Definitely worth the money. I used to have the Sette chain cleaner from Pricepoint and I went through 3 of them in two months. The plastic was brittle and I was using Finish Line cleaner and degreaser and it made the plastic fracture. Pricepoint replaced them and I finally just took a store credit and ordered the Park tool cleaner. I used to have the Pedro's cleaner but is was difficult and messy to use.

Another one for the Park. It even works on my fixed gear.