You know you can use water when you're claying - absolutely no need to use special spray.
I used to use Poorboys spray, ended up watering it down and after talking to some guys at Polishedbliss you can get away with using water (just use plenty from one of those plant spray bottles).
Yes I know this but I clay once a year and after the claying is done the spray bottle has 3 quarters of lubricant left which lasts me the remainder of the year (almost anyway) as a quick detailer after each wash when drying and getting rid of water streaks/spots. Basically a surface cleaner thereafter.