It was, he insists, a vast change from his daily life as a science teacher at Brislington comprehensive, near Bristol. The 34-year-old took part in Regency House Party, a nine-week reality television series for Channel 4 which begins broadcasts next month.
Participants spent the summer in a country house, as ladies and gentlemen of the early 1800s. Each took up a different position on the Regency social spectrum. At the top were the moneyed Countess and the landed gentleman. At the bottom were the penniless lady's companion, and Mr Foxsmith, a pound;200-a-year cleric.
His lack of wealth was not the only link between his 18th and 21st-century jobs. Clerics often studied science, and Mr Foxsmith used this as a basis for experimenting with Regency equipment.
"I could stay up all night looking for Uranus with my telescope," he said.
"I would go out and watch bats at night. And I had a leech on my forearm for an hour and a half, to remove impurities. It was utterly brilliant."
But he was frustrated in other scientific ambitions. Brislington is renowned for its collection of orchids and Mr Foxsmith hoped to sketch some. But he said: "The ladies were into herbalism and picking flowers and I was told it shouldn't concern me. It wasn't a gentlemanly thing to do."
As a guest, protocol required that he ignore household staff. He found this particularly awkward when they were helping him to dress and shave in the mornings.
And there were other disadvantages: "We were given some rags and a chamber pot, and left alone. That's when the walls of reality came crashing in."
But, he adds, the disadvantages were outweighed by the benefits: "The Regency was a time of massive explosion in science. I hope I can use this to help children's understanding of science."
Regency House Party will begin on February 7.