https://www.thevespiary.org/rhodium/Rhodium/chemistry/grignard.wet.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/grignard.wet.html)
A reaction was performed using diethyl ether that had been shaken with water, the mixture then being allowed to stand for one hour. The ether was so wet that 1-bromobutane formed a cloudy mixture when it was added. The reaction of this mixture with magnesium proceeded satisfactorily after sonication for about 50 min. The yield of product alcohol was about 50% (GC).
Read it and shake your head in disbelief. I sure did when I saw it for the first time, remembering those fucking bromobenzene nightmares that would refuse to start. Your 4A mol sieve is not even necessary when you have an ultrasonic bath.