I've done this to my flyknittrainers and racers.
Take the insoles and laces out. Pre-treat with some mild detergent and use a soft brush to scrub. Throw them in the wash.
The only thing if I am not sure is how the boost material will hold up after washing them in the washer.
If you don't want to do that then in se mild detergent and was scrub with a soft bristle brush and rinse.
Let us know how it goes.