The former Great Britain forward said that he was not getting a response from some of his players and also blamed abuse from a section of Batley's supporters.
"After 28 years in the game, I didn't need the sort of abuse I was getting from a small minority of the crowd," he said. "It was beginning to get to me and, if I'd stayed around, I might have done something I would not have been proud of."
Batley would have been promoted to the top division last year for the first time in their history if it had not been for the reorganisation involved in Super League. But they finished next to bottom in the new First Division in the last winter season and have won just one match this time.
"Players have gone and not been replaced," said Grayshon, whose long playing career included successful spells at Dewsbury and Bradford. "It will feel strange being out of the game after all this time, but it hasn't really sunk in yet."
Salford, hot favourites to win the same division and promotion to the Super League next season, have set their sights on signing Andy Platt, the former Wigan and Great Britain prop, who is due to return to England after two seasons with the Auckland Warriors.
Auckland's coach, the former Wigan boss John Monie, is being linked with the vacancy that will be created by Brian Smith's departure from the Bradford Bulls at the end of the season. Like Platt, Monie's contract at the Warriors expires at the end of this season.
Iestyn Harris, Warrington's Welsh international stand-off, is the Stones Super League gold award winner for his performances during June.
The meeting of the Rugby League Council that will decide whether to fast-track South Wales and Huddersfield has been set for next Friday.Reuse content