That's great they have gone on the potty. Statistically, boys are generally later and twins are generally later. Anyway, I highly recommend the bjorn potty. It worked WONDERFULLY for my boy now 2.5 years old. He loved it, and everything went in it just fine. It's only 9.99 at babies r us, which is real good when you are buying 2 for twins. :) I don't know what you've done with juice, but I avoided juice until potty training. Then he got juice ONLY when he was sitting on the potty. It helped him to "stay put" and it also gave him ammunition to actually go on the potty. He potty trained really easily for me that way. He started out sitting on the bjorn potty, then he would stand and pee on the bjorn potty and then he transitioned smoothly to the big potty and only uses the big potty now. We went with his timeline and just encouraged him along the way and it worked great. Just some thoughts...as that's what worked well for us. Best wishes to you with your twin boys!!