I'm not ashamed of my home, not in its appearance, upkeep, or conditions. But I would never allow my son's teacher to come to my house for such a visit. In my son's life, my place is at home and at school, but his teacher's place is at school.
I always thought home visits a bit paternalistic and judgemental, because I was told their reason was for the teacher to get an "understanding" of the child's home life. I viewed them as one link in the chain of soft bigotry of low expectations.
Here, however, is a justification I can live with and support:
The concept is simple: Students will do better in school if their teachers and parents get to know each other. The grants go to schools that predominantly serve children from low-income families.
Building a bridge is good. Acting like a social worker after a two-hour in-service on what to look for in a home visit is not.