In those threads linked to and others, some have charged an item or two to the hotel room and had the bill go through to generate points and an "official" stay and day. No guarantees however; you book via a third party and
... Specifically excluded from the definition of "stay" are the following types of ineligible stays: wholesale/tour operator packages; contracted crew rates; travel agency discount rates, packages exclusively for casino player card holders; Team Member Travel rates, Hilton Family Travel Rates; stays secured utilizing Hilton Grand Vacations Club and Hilton Club timeshare programs, Hilton Grand Vacations marketing packages with a sales presentation requirement; complimentary or barter rooms; Reward Stays (as defined herein); NET Group rates; Series Group or IT Group rates; contracted Entertainment or Encore rates; third party websites bookings (irrespective of rate paid); and "opaque" channel bookings where the brand may or may not be known at the time of purchase. HHonors Points (or stay credit) may not be earned (including as a My Way benefit) for or during ineligible stays, including without limitation, folio charges incurred during ineligible stays.