I only recently learned it's painless(?) to make oat milk with one of those; I got one of these (https://www.amazon.com/Vegan-Milker-Kitchen-Wooden-mortar/dp...) but realistically I think any deep container and then straining out the oat pulp with a normal sieve would be just as effective. I haven't tried it with alternative milks (soy, rice, almond) because I'm happy enough with oat milk and it is incredibly inexpensive