Last summer I took one of the twistees from a store and cut it up in quarters and within 3 weeks those segments were pushing new growth from the base section that was put into the ground.
The big draw back to that is those plants from the quartered top are much, much, much smaller than the twistees that I just put into the ground whole.
From the looks of it, the quartered ones will need at least another year, maybe two before the will throw a flower. Comparing those to the whole ones I put in the ground last summer is night and day - my whole ones are getting enormous and I'm guessing will end up flowering and fruiting this summer.
Just be prepared for the results to take a while if you use very small cut pieces. A LONG time.
IF you're looking for more plant material, besides the local supermarkets you can always try going to the smoothie king franchisee in your neighborhood and asking there as well. Its hit or miss but if you find somebody into recycling you could end up with an easy 50-100 tops and have plenty of material to get you going. On my end I usually buy 1 pineapple a week at our local bodega so I've just been adding one new plant a week. I get about 85% take rate with much better take rates in the summer than the winter time (summer was almost 100% take rate, winter has been about 60% take rate).