How to pack laundry supplies for long trips

Pack a small bottle of laundry detergent (2-3 oz), a sink stopper or collapsible basin, and a microfiber quick-dry towel. Most destinations have laundromats or hand-washing facilities—you don't need much. Leave room in your luggage for dirty clothes.

Choose your detergent format. Buy a small 2-3 oz bottle of liquid laundry detergent or pack 4-6 laundry sheets (they're lightweight and take up almost no space). Avoid powder detergent—it's heavier and takes longer to rinse. Dryer sheets are optional unless you're hand-drying everything. Detergent sheets work best for trips over 2 weeks.
Get a sink stopper or collapsible basin. Pack a rubber sink stopper ($3-5) or a collapsible silicone basin ($8-12). If your hotel sink doesn't have a stopper, this lets you hand-wash clothes. A basin is lighter and more reliable across different sink types. Don't rely on finding one—bring your own.
Add a microfiber quick-dry towel. Pack one lightweight microfiber towel (under 4 oz). Use it to wring out wet clothes and lay them flat to dry. It's much more compact than a regular towel and dries faster than cotton. Brands like PackTowl or REI make travel versions.
Consider a clothesline or hanging solution. For trips longer than 10 days, pack a lightweight paracord clothesline ($5-8) or adhesive hooks ($3-5). Many hotel rooms lack good drying space. A 6-foot clothesline weighs almost nothing and solves the problem. Use it between bathroom fixtures or hang it in your room.
Plan for laundromat access. Research laundromats in your destination before you arrive using Google Maps or travel forums. In most cities worldwide, laundromats exist and cost $3-8 per load. This is your backup plan for trips over 3 weeks or when hand-washing isn't practical. Bring quarters or small bills in the currency you'll need.
Pack strategically for dirty clothes. Leave 20-30% of your luggage space empty or use a lightweight packing cube as a 'dirty clothes' separator. Rolling clothes compresses them; this applies to dirty clothes too. Don't buy a separate laundry bag—use a regular stuff sack or even a plastic grocery bag.

Can I just buy laundry detergent at my destination?: Yes, but only if you're staying 2+ days and have time to shop. Detergent is available in almost every city, though prices and selection vary. For trips starting immediately after arrival or visits to remote areas, bring your own. Laundry sheets are cheaper to ship in your luggage than to buy abroad.
Is hand-washing clothes actually practical on a long trip?: Hand-washing works for 5-7 items at a time and takes 15-20 minutes. It's practical for 1-2 week trips if you have good drying space. For 3+ weeks, use a combination: hand-wash socks and underwear every 3-4 days, use a laundromat every 10-14 days for larger items like shirts and pants.
What if my hotel doesn't allow hand-washing clothes in the sink?: Most hotels don't explicitly forbid it, but ask first. If they do, use the bathtub instead—fill it with 3 inches of water. Or locate a laundromat nearby and use it every 7-10 days. Some accommodations offer laundry service; budget $1-3 per item if using it.
Should I pack a plunger-style hand washer?: No. They're bulky and unnecessary. Your hands work fine for agitating clothes in water with detergent. A plunger adds weight and takes up space better used for other items. Save the space.
How long does it take clothes to air-dry in a hotel room?: Cotton takes 24-48 hours indoors without airflow. Synthetic blends dry in 12-24 hours. Speed it up by: wringing hard with your microfiber towel (removes 30% of water), hanging near a window or fan, and separating items so air circulates. In humid climates, drying takes 2-3 times longer.
Can I pack a portable washing machine?: Sonic and hand-crank washers exist but aren't worth it. They're $30-60, weigh 1-2 lbs, take 30 minutes per load, and still require drying time. A sink stopper and detergent sheet accomplish the same thing in less space. Skip it unless you're on a 30+ day expedition.