when i give my kids dramamine (for long car rides) within 20 minutes they are passed out-- slumped over with drool down their shirts. i would not try to use this medicine while at disney or you will have miserable kids (and parents).
the problem is that young children are not supposed to take the "less drowsy" dramamine and bonnie. i believe someone said there is one for kids, but i have not seen or tried it yet.
i'm worried about this topic myself. my two younger ones have had horrible carsickness since they were about 8 mos. they will start vomiting often within 5 minutes of the house. it has been very stressful and we don't leave the house with them too often. we also always have multiple trash cans, bags, wipes, clothes in our vehicles. i'm really hoping they're not going to be sick on every ride at disney.
i recently bought sea bands for them. they're acupressure bracelets that you can find near the motion sickness meds in most stores. i didnt think they would work, but they do seem to help. they still get sick feeling, but they have only gotten sick in the car when i've forgotten to put them on.