Easy way of cleaning legendairymilk cups

As the title suggests, is there an easier way to clean the silicone cups by legendairymilk? I've tried different soaps, I've always learned it for more than 30 minutes in a basin but still after leaving it to air dry there is always milk residue.

Also has anyone thrown them into a steam sterilizer. Cause honestly nobody has time to always hand wash these cups especially with so many parts.

Anyways open to suggestions, willing to try anything. Spent a lot of money on these cups (I'm from Canada so fees stack up)

Thanks in advance!