I had great luck with those bulbs. I bought about 6 packs of them (being sure to get the packs that had the most bulbs in them, I think they pack them by weight) thinking that maybe I'd get 5 or 6 plants out of them.....I was shortly overrun with lilypads. One bulb had 3 or 4 sections, and they all sprouted, and I'm pretty sure all but 3 of the bulbs sprouted out and grew like wildfire. I say pretty sure because the pleco thought the unsprouted bulbs were great to nibble on....there were only 3 duds left in the tank after a month or so....
The trick is to put them in your tank between water changes, so that there is plenty of planty-munchies in the water and substrate to jumpstart them. Whenever I set my tank back up (if I go with fw, that is) I'm definitely buying Walmart out of them....