First off since bf readings are so inaccurate, I'd do that about once a month if that. Secondly, I'd cheat once a week and have one cheat meal then eat clean the rest of the day. You want to elevate the metabolism and crank it up a bit, you don't want to thwart your entire weekly progress. Remember as you lean out more and more, you have to lower you kcals and/or change the macro breakdowns.
~SC~