It's hard on young hands - scrubbing and sudsing for hours on end. All that wringing out, can wipe you out.
Enter - the bici-lavadora. "Bici" comes from bicicleta, which is the Spanish word for bicycle. Lavadora is the Spanish word for washing machine.
A re-tooled steel drum holds the clothes, the water and soap, and pedal power does the rest.
Seiberg reports it is pretty easy to use - there's one gear for wash, one gear for the spin cycle, even one for rinse.
Massachusetts Institute of Technology student Lisa Tacoronte says it's important the locals learn more than just how to use it.
"We teach them how they can take it apart, how to maintain it and repair it," Tacoronte said.
The bici-lavadora was born in a obscure corner of MIT. The school's experimental D-Lab, for Development, specializes in simple solutions to third world problems.
The washer was a show-stopper at a recent World Development Expo. At $125, it's already used in Guatemala and Peru, with more countries to come, saving time, electricity and precious water.
"We're teaching these children the importance of recycling and saving valuable resources," said Lily Bevries, the orphanage director through a translator. "Like water, which in many places is in short supply."
"Is there some reward for you in doing this sort of socially-responsible work as opposed to going off and trying to make millions of dollars?" Seiberg asked Tacoronote.
"It's a little more self fulfilling and I think I value the connection I make with these people," Tacoronte said. "And it's just I feel like I'm really doing something productive."
The kids love the new machine, and the clean laundry it produces.