I have no idea of the legal definition of pastueurisation in USA law.  I
suspect your customer has little idea of the nature of honey.  Nearly all
honey will crystallise in time.  There are a few exceptions such as ling
(calluna vulgaris) which forms a thixotropic gel.  If you warm your honey only
sufficiently for it to flow this cannot be described as pasteurisation which
is unnecessary as honey itself kills bacteria.
I suggest you sell this customer only crystallised honey.  This can be
achieved quickest at about 57 degrees F,  particularly if it is seeded with
crystals.  Higher or lower temperatures will delay the process.
Chris Slade