Senators have largely stuck to water, but at least two -- Burr and Sen. Tom Cotton, R-Ark. -- were spotted with a glass of milk this week.
The allowance for milk stems from the 1950s, when milk was thought to be a good treatment for ulcers, according to Sen. Bill Cassidy, R-La. The ban on coffee doesn't really faze him.
The sludge in the Republican cloakroom is so bad "you'd wish it on a Democrat but one else," he said, and in a nod to the partisan nature of the impeachment inquiry, quickly added "just joking."
Snacks and gum -- while technically banned -- have been heavily deployed. Sen. John Thune, R-S.D., chewed gum with vigor in his first row seat Thursday. In the back of the chamber, Sen. Chris Coons, D-Del., shared his supply with neighbor Sen. Amy Klobuchar, D-Minn. Sen. Kamala Harris, D-Calif., has a stash of Reese's in her desk.
But trial snacks don't come without risks.
"If this thing goes on, we're all going to gain like 10 pounds," said Sen. Ron Johnson, R-Wis. " 'Another break? Gotta have another candy.' "
While the candy ban has been broken, senators have largely adhered to the cellphone prohibition.
It has served as a form of detox for lawmakers accustomed to frequently checking email and Twitter.
"It has been liberating," said Sen. Patrick Leahy, D-Vt. "I think it's great not to have the computer."
"It's kind of refreshing," Sen. John Kennedy, R-La. He's spending his time taking down questions he plans to ask the lawyers during 16 hours of question time expected next week.