Leather
Braided cow-hide isn’t made for water. Take the band off to swim, shower or train hard, and wipe it down with a damp cloth when it needs it. Keep it away from perfume, sunscreen, lotions and repellent, and out of long stretches of direct sun. A little leather conditioner once in a while keeps it soft.
Paracord
Tactical 425 paracord is fine to get wet. Rinse it in fresh water after salt water, and when it needs a proper clean, hand-wash it gently in cold or lukewarm soapy water and let it air-dry before you wear it again. Bleach and solvents will weaken the fibres.
Beads, bands and couplings
They’re 3D-printed PLA. A soft cloth is all they need. Keep them away from heat: a hot car or a windowsill in full sun can soften them.
Clasps
304 or 316 stainless steel, so they resist rust. Rinse and dry them after salt water or sweat, and skip abrasive cleaners so the finish stays matte.