>>These hygenic queens are advertised to have ability to clean up AFB.

Keep in mind that the queens YOU get may not be hygienic.The queen raisers are selecting breeding stock that IS hygienic,but all commercially sold production queens are open mated.The breeder hopes the queens mate with his selected drones,but some are going to mate with drones of unknown origin.Even though not 100%,the breeders who are doing this should be supported(buy their queens)because if they quit no one else will do the work.It is a work in progress.The more of these queens one buys the better the percentage that will show hygienic traits.