Something weird is going on in Washington, D.C., and I'm not talking about politics. It's the big white marble dome of the Thomas Jefferson Memorial. The caretakers of the beautiful structure are flummoxed by the moldlike gunk that has begun collecting on it, turning it from white to a dingy, dirty mess!

So far, experts have managed to give the gunk a name — biofilm — and have determined that it's a combo of algae, bacteria and fungi. The question is how to treat this icky stuff without damaging the soft marble, so it remains safe for the environment and visitors.

When I read about this situation I, of course, knew what to do. But I won't be calling anytime soon to share my directive, which would include a helicopter with a huge sprayer and several hundred thousand gallons of one of the most amazing products I've come across in a very long time.

However, I am excited to share the product with Ruby, who wrote the following message.

Dear Mary: Awhile back you offered a method to remove moss and mold from a concrete patio. I misplaced that column. Could you tell me the product one more time? Thank you. — Ruby

Dear Ruby: Yes! You are referring to a wonderful new product called Wet & Forget Moss, Mold, Mildew and Algae Stain Remover. This outdoor stain remover is like no other. It's noncaustic and nonacidic, it contains no bleach, and it's safe on any outdoor surface. What's even better is there's no scrubbing or rinsing required! Simply spray it on, and let it dry.

Really bad stains may require multiple applications. The product comes concentrated. You mix it with water according to the label, and then pour it into an ordinary pump-up garden sprayer for application.

Wet & Forget can be used on any outdoor surface, including asphalt (blacktop), AstroTurf, aluminum siding, awnings, brick pavers, composite decking, concrete, driveways, docks, fiberglass boats, fiberglass shingles, fiberglass hulls/topsides, greenhouses, gutters, inflatable dinghies, limestone, marble, marinas, natural stone, outdoor furniture, outdoor planters, painted surfaces, patios, patio furniture, plastic houses, recreational vehicles, retaining walls, sails, sandstone, shade sails, sidewalks, stucco, tennis courts, teak decks, textured finishes, tiles, tombstones, outdoor umbrellas, vinyl siding, wood and, I believe, big white marble domes!

Wet & Forget is available at Amazon, for about $37 for one gallon, which makes 6 gallons of ready-to-use solution. Some stores, such as Home Depot, Wal-Mart, Lowe's and Ace Hardware, carry it, too. Please visit my website for links to Wet & Forget and more information.

By the way, you don't have to worry about misplacing a column again — even those that do not show up in your newspaper — because they are all organized and filed for you on EverydayCheapskate.com. Once you're there, use the search box in the upper right-hand corner to type in a keyword or two. Be patient once you press Enter because the search engine has to look through thousands of posts. I think you'll be amazed.

Mary invites questions, comments and tips at mary@everydaycheapskate.com, or c/o Everyday Cheapskate, 12340 Seal Beach Blvd., Suite B-416, Seal Beach, CA 90740. This column will answer questions of general interest, but letters cannot be answered individually. Mary Hunt is the founder of www.DebtProofLiving.com, a personal finance member website and the author of "Debt-Proof Living," released in 2014. To find out more about Mary and read her past columns, please visit the Creators Syndicate Web page at www.creators.com.