I used Standard Kshar Sutra of my own preparation, to test the efficacy and strength it was used more than 7 years , it was found same as freshly prepared.
There are some problems in the preparation of Kshar Sutra as hygroscopic nature of Apamarg Kshar, season boundation in collection of Apamarg plant and Snuhi Ksheer, difficult availability of these plants etc.
To overcome these problems alternative Kshar Sutra can be prepared.
I prepared Gugglu-Tankan Kshar based Kshar Sutra in 2014 in which concentrated aqueous solutoin of Gugglu was used in place of Snuhi Ksheer and Tankan Kshar in place of Apamarg Kshar, remaining procedure was same as Standard Kshar Sutra as mentioned above.
Tankan Kshar is easily marketed as Borex commonly called Suhaga.It can be obtained in the pure form by heating which is powdered with the help of mortar and pestle.
Gugglu can also marketed.It is dissolved in water and solution filtered with fine mesh.
I observed in the application of Gugglu- Tankan Kshar based Kshar Sutra patient feel less pain and bleeding rather than Standard Kshar Sutra but due to slippery and hard nature of thread knotting has problem and threat to loose.
I also prepared Tankan Kshar- Snuhi Ksheer based Kshar Sutra in 2015 in which Tankan Kshar was used in place of Apamarg Kshar and the remaining procedure was same as in Standard Kshar Sutra. Here the sticking problem found during prepration as compared to Apamarg Kshar but efficacy found same as compared to Standard Kshar Sutra.