There is quite a range of litters available, but unfortunately, as far as Im aware, the ones in the regular stores (not online) are not that good in Australian conditions for odour help, and vary in clumping.

The key things to look for in suitable Robot litter are

·  fast clumping (less waste and can set to fast 3 minute cycle)

·  low dust (less cleaning)

·  carbon or activated charcoal (for odour in summer conditions)

Im not sure how many cats you have, but I find 1kg per cat per week a pretty good indication of litter needed, so if you can work with deliveries, maybe bulk  order online if you have the space. Our  Premium litter comes as 2x 9kg bags, within an outer bag, so its easier to handle once received, and store. Its about $3.50 per kg, INCLUDING DELIVERY (Aust Post), so medium-priced (18kg minimum). For my one cat, my order lasts me 18 weeks. You can check it out here https://catevolution.com.au/premium-clumping-cat-litter.html 

We have a few customers say its too dark - both for tracking impact on light floors, and for white cats (50 shades of grey). We are actually looking at a second one as an alternative, to provide a lighter option, but less carbon will mean less odour control, so it can be a compromise. 

Try and avoid any scented litters as they are like perfume and mask, not attend to, odours. They are also strong in the semi enclosed globe and use up the carbon effectiveness in the carbon filter faster.

I dont think there are any on the supermarket shelves with carbon or charcoal. Some of the specific pet stores like petbarn etc do sell, but you would need to review what they have.

I do hope this helps - a better litter with carbon or charcoal is really helpful for Australian conditions, particularly as it heats up.

For sticking, it comes down to clumping time for each litter, and also your cats output (urine). Courser litter maybe better for large urine output, but generally means no odour help and dusty. For example Aldi Clay Clumping litter. 7 minute to 15 minute clump time required, depending on humidity and output. Smearing and marking on the globe as the soiled waste is disposed of generally indicates not sufficient clumping time has been allowed for the litter in use. 

If you have carbon in the mix, then clumps sticking to the liner is not a great issue, as the odour is controlled until next cycle, when the liner design helps to dislodge now set clumps. The liner has a weight on the underside and is designed to drop down for this reason. 

Good clumping is a function of fast clumping litter generally, as part of the action.

There are other litters that are non-clay. Applaws crushed walnut shell is in use by some of my customers and they think it works well. It does put sawdust through the base, but the natural timber smell seems ok and it clumps ok in the Robot. You can also explore corn clumping, but note that Tofu and Paper based are not suitable. Even with Applaws, some adjustment of the cat sensor maybe needed as it is light for Robot use.

If you are happy to keep using clay, you can also mix it up, with a basic litter and a better quality litter. For example, our premium will still provide good odour help and fast clumping, but gets more structure for large output if 25-50% mix with Aldi Clay Clumping litter (helps on pricing too).

If your cats are transitioned, generally testing other litters is problematic, and I recommend not throwing out litter, but topping up with the new and monitoring progress from there. If changing type (ie clay vs plant) then a clean start is in order.

PS if you find one you like, let me know as I do pass on for others. We are not specifically a litter company, but bring in what we think is most suitable (after testing many) for Aussie conditions. And a lot of Robot owners agree ;o) 

Dear Kimmie, yes indeed, you can use the litter in the normal trays.