Yes, it is most certainly them. And if you've ever heard the original version of Mother Mary, the woman speaking French may or may not be a former SonicLiving employee.
Just in case there was doubt, there's a wiki on it all:
http://en.wikipedia.org/wiki/Foxboro_Hot_Tubs
The Foxboro Hot Tubs is an American garage rock band. The group made its first appearance on the music scene in December 2007, debuting three songs on its website, foxborohottubs.com. Soon after, Foxboro Hot Tubs were discovered and subsequently made headlines, being heralded as the next secret side project of Green Day, [1] which was later confirmed by the band themselves.