When Mr. Brady is setting up the snowfall mechanism for the play, he is filling it with SAFE laundry detergent as snow.
In season 3 ("And Now A Word From Our Sponsor"), the family was paid for their commercial with 2000 boxes of SAFE detergent, so it stands to reason that they have plenty of SAFE to spare.
The play script has Benedict Arnold demanding £10,000 from the British. In fact, Arnold was paid £20,000.
There was a season three episode titled My Sister Benedict Arnold.