Nature of Operations and Summary of Significant Accounting Policies - Schedule of Changes in Allowance for Doubtful Accounts (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Receivables [Abstract]
Balance, beginning of year	$ 370,000	$ 321,000
Provision for doubtful accounts	290,000	194,000
Provision for estimated returns and allowances	335,000	267,000
Uncollectible accounts written off	(65,000)	(81,000)
Returns and allowances issued	(385,000)	(331,000)
Balance, end of year	$ 545,000	$ 370,000