i'm probably going to go against the grain for most nail companies out there, EzFlow included, but you could always try using a brush cleaner. hold your brush in there for a few mins to allow the acrylic to soften and gently wipe out onto some paper towel, repeat if you need too. i don't always advocate the use of a brush cleaner especially on a regular basis as it can cause you bristles to dry out, but if you use a good quality brush cleaner containing conditioners you should be ok this once. just make sure you then clean your brush thouroughly in monomer before you begin to work again to remove the brush cleaner and to recondition your brush again