Disposable diapers are a blight on the planet and the pocketbook of parents everywhere. They are made out of plastic and go into landfills. Soiled diapers are toxic waste but they are hardly ever treated as such.
Even when the cost of diapers are around 10 THB (~$0.30 USD), with upwards of 4,000 diapers in a babies diapering lifespan we are talking 40,000 THB, over $1,000 USD. I've found a great source of reusable diapers on Ebay out of Hong Kong for less than 250 THB/each including delivery. Even with something like 30 to start out with, we are looking at 7,500 THB. Add in the buckets, bucket liners, electricity, water, laundry soap, clothesline, clothespins it is something like 100 THB/day or 12,000 THB. A good washing machine costs about 9,000 THB in Thailand. Even doubling washing costs would still clock in at the same 40,000 THB, but in the end you still have diapers and a washing machine!