Slimes in minecraft

Hello community, I have been playing the minecraft xbox 360 edition since it came out. I have been looking for the so called illusive slimes. I'm playing on an older map seed that does not contain clay. The map was mape about a month before the first bug update was released. I have wanted to find slimes in preparation for the 1.7 update with pistons, but i have had failure after failure after finding them. I have made multiple rooms in certain areas of the map at certain depths and watched videos as many people have had success doing the same thing. (My friend has a map seed the same age as mine and he has no problem finding slimes) What should i do to find these slimes?Multiple have told me that slimes DO spawn on older maps like mine. Any information or help would be greatly appreciated.

Try using this slime finder tool or this one.

I'm still playing a pre-patch world and I just found slimes yesterday. All I did was dig down to bedrock and started using TNT to clear about a 50X50X6 open space. Lit up the area with torches and after a few minutes they started spawning and they respawn just about every time I go back down there now. Might have been just luck finding it in the first area I cleared though.

Turn it off peaceful.