Loofah Sponge
Did you know a Loofah is a fruit made on a vine (like grapes, cucumber, watermelon etc)? And that the Navy used them for engine oil filters in WWII?
The modern era in the history of its cultivation began in Japan where, between 1890 and 1895, the sponge gourd was first grown commercially.
 The initial justification for the culture of sponge gourds on a commercial scale is based on the particular fitness of their skeletal network for many practical uses, and the special emphasis on their increased production is due to their successful employment as filters in marine steam engines and also in diesel engines.
This special use had made them important to the United States Navy.
Since the time Japan started growing and exporting sponge gourds, almost the entire commercial supply of the United States has come from Japan.
Japan's biggest customer for loofah sponges up to World War II was Germany which bought more sponges than all other countries.
After Pearl Harbor this supply was suddenly cut off. The same catastrophe which stopped their importation enormously increased the need for them, constituting at the same time the greatest single stimulus to their wider distribution and cultivation.
Official recognition of the great importance of the sponge gourds was given on April 8, 1942, when the War Production Board, in order to conserve the country's stockpile, issued an order forbidding delivery, sale or use of loofah sponges except on the highest priority. Not only was the worth of sponge gourds thus officially established, but under a program of encouragement, the U. S. Government by this one official act gave considerable impetus to its spread to fresh regions where new sources of supply might eventually be established.
Attempts to grow loofahs on a commercial scale in the States of California, Alabama and Florida were not successful, but the tropical countries to the south (Mexico, Haiti, Cuba, Dominican Republic, Salvador, Guatemala) in a year's time were cultivating and exporting sponge gourds to the United States.
Before World II, 60% of the imported loofah sponges were employed as filters, which indicated their usefulness to the U. S. Navy, and 40% of them were applied to civilian uses. However, it can be said that, besides filters for the Navy and for steam engines in general, the military uses of sponge gourds range all the way from surgical operations to cleaning windshields of jeeps.
The special use of loofah sponges in steam vessels consists in tile fact that water condensed after expansion in the engine is passed through several layers of closely packed loofah sponges to rid it of oil and dirt before it enters the boiler to be used a second time. Substitutes were tried when the supply of vegetable sponges was suddenly cut off, but all of them proved unsuitable.
Loofah sponges have a similar use in internal combustion engines, such as diesels, except that the filtering function here is to remove carbon and metal dust from the oil.  
Because of their peculiar structure, loofahs made fair shock absorbers. This useful aspect, as well as their capacity for absorbing sound, has been exploited in steel helmets and armored vehicles of the U. S. Army.

https://www.nationalgeographic.com/premium/article/strange-history-common-everyday-things-important-human-lives