Litter Training Dogs

[smramirez]

I am attempting to litter train my 3 dogs: a male chihuahua, a male miniature schauzer, and a female miniature schauzer. I am using Purina secondnature Dog Litter (its the only one I can find). It is a paper-based pellet type of litter. I have aquainted all of my dogs to it so far--the litter box that is. All of them seem okay with it except for my male miniature schauzer.
Does anyone have any tips on how to coaxed them into using the litter box even though they are potty trained for the outdoors? They are all about 2 years old. I know its a little late in their lives to be retraining them, but I am going to be moving soon to either a house without a backyard fence or an apartment. I won't be able to take them outside all of the time and I don't want to crate them all the time, plus I don't trust them on their own outside.
Any suggestions or help will be greatly appreciated.

[Furkin]

you won't be able to take them out on a leash? Some dogs have a very difficult time learning it is ok to mess in the house after being told for years not to. You may also want to put puppy pads in the box instead of litter, dogs do not bury their messes anyways, it's a cat thing. I suppose you could start by teaching them to use the box outside. Bring it out and make them stay in the box (that is another reason I don't like them...the dog does not get to move before going potty) and praise with treats once they go, do this for a while until the choose to use the box. then hopefully they will use it inside too, praise and reward every time they go in it.