how much of the cage are you cleaning?
gliders mark their territory with scent glands and pee.
If you start cleaning the whole cage they will just want to mark up that much more
of the cage, working even harder to mark their territory.
we clean out the pee and poo tray at bottom, that takes care of most of the smell, but we wipe down part of the cage with paper towels using a solution. (wife makes it up, think it is part water part vinegar).
I have also been told a high protein diet can cause their pee to be stronger smelling. If ours start to smell my wife will ask me to slow down on the mealworms and yogurt treats.
We picked up a few gliders a while back. the owner started cleaning just half the cage and the smell started getting better. but the gliders were not grooming and they used baby wipes to clean the gliders. I think that was a big mistake, what glider would groom with all the baby wipe chemicals on them. We got them and one had matted hair in some areas, and two were brown/yellow.