That will be an acid bath ! had one in the pub i worked at,very good bit of kit .I used to charge £50 but that`s going back a few years now.
Best tool i found for getting glass doors clean and most of the bottom and sides,was a window cleaners blade type thing in a holder,much better that getting nasty chemicals everywhere !
Used to do a reg 1 in cambridge,but the blokes very young son always took to much interest in what i was doing,had to tell custy several times to keep him out the way due to the chems i was using,he always came back a few mins later though,had to stop doing that one as it`s too risky having kids around those chems