Materials shown include plastic and silicone for handles and parts; polypropylene and synthetic rubber bristles; natural sea sponge (sea wool); and rayon-from-bamboo washcloths (listed as both 100% rayon-from-bamboo and a 70% rayon/30% cotton blend).
Reach features include foam tips for bottle bases, flexible necks for better access, and silicone or ridged detail cleaners for small openings. Drying and hygiene features include upright stands or suction bases for drainage and ventilated/pour-spout designs that help parts dry quickly.
Several listings explicitly note “BPA-Free” for brushes and cleaning kits, and at least one bottle brush is described as “completely metal-free.”
Natural sea sponges are described as ultra-soft, highly absorbent, hypoallergenic, and abrasion-resistant; they reportedly grow to about 4 inches when wet. Listings recommend rinsing before first use and replacing the sponge about every 8 weeks.
