i have multiple birdbaths, and the rough surfaces of the fiberglass and resin ones in particular have always been extra tough to clean (probably similar to cement/concrete baths) — sponges get torn up and disintegrate, toothbrushes have proven to be too small and/or soft to do a thorough job, and the bristles on other scrub brushes have crumbled to bits under pressure. i wasn’t super optimistic when ordering this dedicated birdbath brush, but after using it this morning i was pleasantly surprised by how well it did — it has a nice large scrubbing surface, the bristles are firm enough to remove persistent algae, and it easily rinsed clean with water. time will tell if the bristles last a decent amount of time (for the price i would hope so), but for now the brush has made a great first impression and i’m no longer dreading this frequent task. (between all the birds and sun during the day and the raccoons making a mess at night, i’m usually stuck deep-cleaning the baths almost every morning.) anyway, if you’ve been frustrated by whatever tool you’ve been using to clean your birdbaths, this one’s worth a try, and hopefully will have a long lifespan.