Ohhhh yuck!!
I usually get the £4 a bag stuff from Tesco but this week, in a bid to economise, I bought Morrison's £1.50 stuff. Oh dear God! Went to change it to day and found it was basically soil. Obviously with my kitten's urine it had all moulded together into a lump of clay and the SMELL. It had only been in the tray for two days but smelled like it had been unchanged for a week!
Can safely say a £4 bag of litter is well worth the money...