I have made ice cream using the rock salt method, and I highly recommend investing in an electric ice cream maker. The first ice cream maker I used had a manual crank, and it seemed to take forever to reach the proper consistency. We all took turns with the crank, and by the end we were all exhausted. The ice cream itself was good, but it took a lot of work.
I found an electric ice cream maker the next year and we followed the same recipe with the rock salt/ice blend around the inner container. The electric motor started to seize up towards the end, but the final product was better. Most homemade ice cream will not resemble the commercial variety, but it is definitely fun to make and even more fun to eat.