There are many methods like checking temperature, using color changing strips. which one is simple and easy to use in non hospital setting like private clinic or at home for consultants?
The most simple and easy method is to use controls. Commercial controls are costly so you can use "ordinary soil in a cloth" as control. After autoclaving grow this soil in culture medium. If it gives growth then autoclave is not working properly. IOtherwise, autoclave is working properly. In case, autoclave is not working properly, troubleshoot it please.