part III of 422 gets into this. I think the LOTO part comes from 422.31(B), not that the average home owner or DIY'er would carry any.
422.34 details the different occupancies
422.34 Unit Switch(es) as Disconnecting Means.
A unit switch(es) with a marked-off position that is a part of an appliance and disconnects all ungrounded conductors shall be permitted as the disconnecting means required by this article where other means for disconnection are provided in the following types of occupancies.
(C) One-Family Dwellings. In one-family dwellings, the service disconnecting means shall be permitted to be the other disconnecting means.
i'm a tad stuck on the verbage here, inparticular the 'other disco means'.....