Note 6 - Warrants (Details Textual) - USD ($)		Sep. 30, 2023	Mar. 06, 2023	Sep. 30, 2022
Share Price (in dollars per share)		$ 0.17
Warrants and Rights Outstanding	[1]	$ 18,000
Note Payable, Maturing March 8, 2023 [Member]
Debt Instrument, Face Amount			$ 50,000
Six-month Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Month)		6 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		5,234,948		13,568,524
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.23
Six-month Warrants in Connection With the 2020 Unit Offering [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.19
Six-month Warrants in Connection With the 2020 Unit Offering [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.23
Five-year Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Month)		5 years		5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		5,234,948		13,568,524
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.29
Warrants and Rights Outstanding		$ 913,000		$ 2,898,000
Five-year Warrants in Connection With the 2020 Unit Offering [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.24
Five-year Warrants in Connection With the 2020 Unit Offering [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.33
Warrants Issued in Connection with Conversion of Interest on Note Payable Maturing March 8, 2023 [Member]
Warrants and Rights Outstanding, Term (Month)			5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 0.21
Warrants and Rights Outstanding			$ 30,000

[1] Aggregate intrinsic value based on closing common stock price of $0.17 at September 30, 2023.