I was never embarrassed by this but did it often:
Fly to Chicago, rent Avis, stay for a week, never in the same Hyatt for more that one night. That helped me get my Diamond level (25 separate stays) and 500 points for each night with Avis! I have also done this between the Sheraton DT Seattle and the Hyatt in Belevue, again multiple dipping my avis rental.