I actually did the month inside thing when I had my son, although I drew the line at bathing. For me as a first time mom it was kind of nice not to have to deal with anything besides my new family for a whole month.
With my daughter though I had had enough after about 2 weeks. Since my family came to visit when my daughter was about 10 days old I also wanted to take them out and about a bit so I told my husband I wasn't going to be doing "the month." Luckily with my daughter the recovery from the birth was a lot easier and I overall felt back to normal a lot quicker than I did with my 1st.
I do think there is some folk wisdom in "the month" but if a woman is feeling up to going out then she should be able to. I don't like the pressure placed on new and expecting mothers here and the insinuation that if she goes out of her house (eats cold things, doesn't wear enough clothes, uses the computer, has a pet, etc) she's doing something terrible and possibly even endangering her life, or worse, her baby's life. The attitude towards pregnancy here, in my opinion, sets the stage for what you see later with the coddling of children (spoon feeding until 4 years old, wearing multiple layers of clothing in 80 degree weather, never allowing the child to fall down ... and on and on until you have the end product, the students we all love to complain about!) and is not always a healthy way to look at parenthood.