Havent' used the Clayton stuff either, but I use Ilford Ilfostop often. It's based on Citric Acid instead of acetic acid, so it doesn't have the odor. However, the dilution is lower (the citric is weaker) and the print load is lower per litre.

Works good, though. It has the phenolthalein indicator also. And, hell, it citric acid...I use the citric acid for preserving fruit as a supplement when I run out and I need some quickly.