We're trying PLing this week too, or at least trying to. The first few days we did a story linehttp://www.do2learn.com/picturecards..._toileting.htm
And we would look at them before going in the bathroom for the first few days, to get the routine. We set a timer and sit for 3-10 minutes, depending on what I think her attention span/needs are. I'm having her sit on the baby bjorn potty, I think it's better to have something smaller, plus I want to be able to bring it with us.
The first few days while we were getting the routine I had her wear pullups, now we're running around nakey (she's 3-1/2 developmental delay/low tone/spd, development about 18-24 months, language is lower).
She doesn't mind sitting on the pot. I reward her with dates (the food, not on the calendar) for going, and lots of verbal praise that she likes for sitting on the potty. She's never responded very well to bribes, which is why all my previous potty training trying hasn't worked. She does respond well to routines.
I'm working with her little brother at the same time, I think that helps a lot as well. He's easier to bribe, and she's more likely to copy him than take directions from me
I'm curious how long this will take. I did buy a book on it- Toilet Training for Individuals with Autism or Other Developmental Issues. Our OT would ask how pottying was going, but her only suggestion was to bribe her with food. That doesn't work really well for my child- so I bought the book and so far it's going better than my previous attempts.