Hi Sally. That method, though scary, works very well. We moved an old stand of Crinums a few years back and they were so congested that some bulbs got whacked with the shovel...most of them did just fine...only the ones that got small pieces of the upper part did not take.
I suggested Crinum because of the size of the bulb in the second picture. My Hymenocallis bulbs are smaller and have a much darker "skin"