I always request no housekeeping for the duration of my stay -- for all the above reasons. In thousands of hotel stays, I've had most of the variations on the above theme, not just at Choice hotels. Seldom, but they are among the things that p.o. me the most. That said, I just would add to the above good comments that I sense that the letter, coming as a followup, is directly from the proprieter/GM, and that's whom you're dealing with. Housekeepers would go directly to her/him because they are easily fired, especially for p.o.ing a customer.
I guess what I'm also suggesting is that you negotiate with the GM/proprieter to get it to every five or four or three days.* Logic and money are on your side, after all. FWIW.
* (It's not uncommon for hotels to have a policy of four or five days. Imagine their worst fear. Not saying it couldn't happen in one or two days, but they just need to have a good story when answering to the authorities for the real reason for that awful smell.)