As a natural extension to teaching, Frank was an engaging speaker. He gave regular lectures and slide shows to local organisations, SPAB and TIMS. These talks were often to groups he was a member of like SIAS and the Brighton & Hove Archaeological Society, as well as to local groups as a means of fund-raising for mill restoration projects. When Polegate Windmill was being restored, Frank even persuaded his wife Betty to host several evening slideshows to people of her acquaintance; between them they raised a lot of money for the appeal.
To have the name of Frank Gregory on the programme ensured a good audience, one person noted that over 100 people had attended an evening lecture Frank had given. After a slideshow on Austria to the RAF Brighton & Hove in January 1957, it was reported that they were “very lucky to get Frank Gregory”. There are few notes for his talks so he probably spoke off the cuff; he was an expert who didn’t need a crib sheet. A report appeared in the Brighton & Hove Herald on 18th February 1961 of a talk given by Frank to the Brighton & Hove Archaeological Society:
The delivery of the lecture was first-class and the colour photography really superb making this one of the best lectures the Archaeological Society has ever received.
Once a mill had been restored, he often remained as part of the management team carrying out maintenance, repairs and opening the mill to the public. Frank relished the role as a volunteer guide at open days: Jill Mill at Clayton, Shipley, Nutley, Park Watermill at Batemans, Michelham Priory, Polegate, Singleton Watermill at the Weald & Downland Museum and West Blatchington Windmill. On fete days, he would often appear in his traditional smock, necker and battered trilby. According to Peter Hill of West Blatchington, Frank found the smock on a scarecrow whilst on a ramble; the scarecrow received Frank’s raincoat in return.
Frank was in his element when a visiting group comprised children. Being a teacher by profession, Frank was a ‘natural’ with children. He was very patient with them and his infectious enthusiasm to seek out, explore and discover are qualities that children readily respond to. He particularly enjoyed showing school groups around various mills: In later years, the West Blatchington tours also included his grandsons. As a result of his work at Park Mill at Bateman’s, he became associated with the Outward Bound Centre at Burwash. He would take visiting groups on rambles to local mills pointing out other interesting features of industrial heritage on the way. After one group had visited in January 1971, Ken Gulliver, the manager of the Centre, wrote to Frank: