I've tried this with Pochi and Choppi (reason they being boys, like to lift their legs and end up getting everything but their pee pad) and Pochi took to it well but Choppi didn't.
Choppi is a little lazy and even with his pee pads he thinks if he has his front paws on the pad it's good enough so he ends up peein on the floor in front of the pee pad, same with the litter box, he would just put his front paws in and go.
Pochi does a great job in the litter box. I use the newspaper litter like Yesterday's News but I had to start them by first putting the pee pad in the box and putting a little layer of the litter on top of the pee pad so they know they are suppose to go in there. Pochi caught on real quick and soon I no longer used the pee pad and just put the litter in the box.
Lots of praises and treats help too!
I still use the litter box for Pochi, as for Choppi? I've given up hope and have him in the bathroom with a pee pad that way I can do fast clean ups for all his "close but not close enough" bathroom duties.
Hope that helps and good luck if you try this!