I have successfully potty trained 2 sets of twins. My first set were fully trained one month before they turned 3. Most recently I traiNed my 2nd set in September. They will be 3 in April. I tried to do this one month after they turned 2. It was horribly frustrating. I put it on hold and tried again in Sept. They were 29 months. I used the 3 day potty training method, which actually took 5 days.
I had to have a full week with not much on the calendar. I bought a bunch panties and undershirts. I kept them in their panties all day. The first day we didn't go anywhere execpt to pick up my older kids from school. We didn't use any diapers at all. Not even at night. I had them "throw away their diapers" (not really though I had friends with kids in diapers still). We had two baby potties in the living room, one that fit on the toilet, a folding travel seat for the store and one Baby Bjorn one piece potty for the park, etc.
We played all day in the living room (we have wood floors)drank all kinds of bad stuff, juice, soda etc, and had lots of crackers to make them thirsty. I kept putting them on the potty every 30 mins or so. The first 3 days were horrible, they fought tooth and nail when it was time to sit on the potty. They would sit on the potty and then pull up their panties and go in them. I almost gave up on the 3rd day, but I didn't want to do this again. After the 3rd day we went to the store, tired to use the potty there and all that jazz. They saw these cute Littlest Pet shop toys and wanted them so bad. I bought them and put them up in the living room and said they could have them if they went in the potty. The 4th day was a little better but they still didn't seem to be getting it.
The 5th day, was awesome. One of them was just sitting there and said "poo poo in the potty" and then went and did it. She was pretty proud of herself and then asked for her Whale toy that she picked out. The other one still didn't want to do it until she saw her sister going all day and having fun with her toy. So, then she decided to go too.
Night time, went like this: We stopped all liquids around 6:30. They go to bed at 8. I woke them before I went to bed so they could try and go. Then I woke them up again in the morning 30 minutes before they normally got up and had them sit on the potty till they went.
It was hard, frustrating, and messy but it worked.
The Baby Bjorn one piece potty is awesome for travel and going to the park. It's only $9.99 and fits in a backpack. We keep it in the car with a bunch of grocery store plastic bags and baby wipes. The bags fit right over the potty and they go in it, and then we throw the bag away. LIFESAVER!!!
I know this was long, but please feel free to email me if you have any other questions.