You may want to try this, since you travel weekly and have left several things behind.

When I go to leave the room the last time, I ask myself "did you get everything?" I go through the room until I get back to the door, and the answer to the question is "yes". *Then* I go back through the room one last time and double check. I usually answer "yes" the first time to the door, but 50% of the time on the "double check" pass I find something (stray sock in bedding, shirt on hanger, shampoo).

As Jeffrey reports below, this isn't the only case where this chain refused to help with misplaced items. I learned my system after leaving a jacket behind. In that case the motel gladly sent it to me, but I realized some places might not be so generous.