I would not wash the top again until it is completed. You are incredibly lucky not having the top come apart in the washer! Synthrapol needs hot water. It keeps excess dye shed by the fabric in suspension so it will not be redeposited on your quilt top. Another thing is you need LOTS of water. An old fashioned top loader at the highest water setting, not a front loader or a HE top loader. Your best bet is to take it to a Laundromat and use one of their big washers.
I also wouldn't stress too much, it is probably less noticeable than you think.