Get a box or two of the super large, super absorbent feminine hygiene pads. They are a good addition to the much more expensive and harder to find "trauma pads".
I'm familiar with that improvision.
I have a twenty-five count box of 5" x 9" trauma pads, thus far one has been used for a first aid kit. Also, trauma pads are not hard to find; they may if the brimstone hits the fan.
Jeanette Isabelle