Note 6 - Warrants (Details Textual) - USD ($)	Mar. 31, 2023	Mar. 06, 2023	Mar. 31, 2022
Share Price (in dollars per share)	$ 0.20
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 (Year)	6 months		6 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	3,656,000		5,196,968
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.228		$ 0.204
Five-year Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Year)	5 years		5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	3,656,000		5,196,968
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.285		$ 0.25
Warrants Issued in Connection with Conversion of Interest on Note Payable Maturing March 8, 2023 [Member]
Warrants and Rights Outstanding, Term (Year)		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