Why isn't it raining?

Hint 1 of 12:

Haven't you heard some folk tales that explain how to create rain?

Hint 2 of 12:

Bernard will tell one of them to you if you look at the car in 1993.

Hint 3 of 12:

Washing a car makes it rain.

Hint 4 of 12:

Or in the past, washing a carriage makes it rain.  There's a carriage just
outside of the inn.

Hint 5 of 12:

All you need to do is wash that carriage, and it will rain.

Hint 6 of 12:

To clean a carriage, you need soapy water and a brush.  Everything you need
for this puzzle is available in this time frame.

Hint 7 of 12:

Get the brush and a bucket from the pantry, and then use the bucket on the
water pump to fill the bucket.

Hint 8 of 12:

For soap, you might need to call housekeeping.

Hint 9 of 12:

Pull the cord in George Washington's room and the maid will come.  And she
has soap out on her cart in the hallway.

Hint 10 of 12:

Before you can get the soap, you need to make sure that the maid is too
occupied to come out in the hallway and can't see what you're doing.

Hint 11 of 12:

Create a mess in the bedroom.

Hint 12 of 12:

Use the bed, and you can take the soap.  Close the door once you're in the
hallway to make sure that the maid doesn't catch you.