i personally have never litter trained but it's never too late to train your dog..the easiest way for me atleast was to keep them in the kennel and let them out every hour until it was bedtime so that they knew they had to go outside..i did that for about a week with my lil girl chi and she's potty trained now..the boy on the other had was trained but started to act up again so we're doing the whole routine with him...it seems to workwell..
i use pads in a litter box (it keeps everything comtained as vixie likes to pee on the very edge lol) most chis DO NOT like the litter as its like little wooden pellets and it hurts to stand on it...however a puppy pad is easy on the feet disposable ect.
and no its not to late...vixie had absolutly NO poty training before i brought her home at 6months old..withint a week of just keep putting her on her pad whenever she started to show sighns she had it down pat and hasnt had an accident since...
Pixie uses a litter box and has no problem with it. I buy flushable cat litter so I don't even have to worry about the smell in the garbage. It gets a little messy so the one drawback is that you really have to keep up with the vacuuming. I started her with the peepads but this seems to work much better for us.