Yup, that seems to work fine. The host country that you select on the site is the country you are "in". If you are "in" your home country, and they charge you in the currency of that country, then it's not DCC. It would be like a BA ticket office in the US charging you in dollars because you bought the ticket and swiped your card in the US. Luckily AirBnB seems to have no problem with you claiming to be located in whatever country you want, so no VPN is necessary.