I've never thought to wash anything in my washing machine other than clothes, but I suppose a laundry bag can make it possible to clean so much more, including small lego pieces! You could also use this concept in the dishwasher.
1. Found old Legos in storage, but they were dirty and gross.
2. Decided to try washing them in the washing machine.
3. Put all the Legos into a large laundry bag and added a bit of soap.
4. Ran the washing machine on a hot water cycle.
5. Took the wet Legos outside to drip dry.
6. Hung the bag initially but found that most pieces were still wet.
7. Opted to spread them out to dry, but didn't have a mesh rack.
8. Left the Legos outdoors for a few days, stirring them occasionally.
9. Legos are now clean and ready for playtime!