Angie, by miltons do u mean miltons sterilising liquid?? if so ive never thought of that ,
i use bleach and boiling water to clean my litter trays then i line them with news paper then tip cat litter on top i fill the trays quite deep ,
i also put news paper on the floor underneath the tray as Bridie has a habbit of poohing on the floor just next to the tray

the wee dont stink unless u put ya face right next to the tray but it just seems like theres no where else for them to pee where all the litter has asorbed the wee , plus Bridie has had a few uti in the past and i like to keep it all clean incase theres any risk of infection from a dirty tray
the litter i use is adsa tiger cat litler or the tesco one , i only like the cat littler thats white in colour as the others seem to make the trays filthy and all mud like , plus max has a habbit of getting in the tray and chucking litter everywhere and i find the white cat litter easier to clean up from my floor,
the people who have said they have 1 tray per cat dont u find they just all use whatever one they feel like thou ?
for example one tray can be filthy and the other hardly used .
it cost a fortune in catlitter which seems a shame considering its only to pooh n pee in lol
my fav is cats san , and theres one in my pet shop called i love my cat its got a cartoon cat on the bag and its a wood pellet based cat litter but i tend to stick to asdas tiger litter as its only £1.98 per 10litre bag .