My sister and I weren't feeling up for an overnight stay in Boston, so we wound up cancelling the stay the evening of (understanding that there would be no refund). John thanked us for letting him know.
We did not wind up accessing the unit at all, so I can't speak for the cleanliness of the space, but looking at other reviews I would say that it shouldn't be an issue.
My sister and I are both in our early/ mid twenties from a fairly rural area and had zero experience traveling by ourselves in Boston, so the area that the AirBnb was in didn't quite feel as safe as we thought. But I think that reflects more on our lack of knowledge about the area more than the location itself (but is worth mentioning for others who might be in a similar situation). Certainly seems a great place to stay if you have a better feel for the area.