Please read @"Rakhi-Certified VK Teacher" Didi's comment for complete details of time frame while charging water .
@apoorvm ji
1. For water upto 2 litre keep VK for 2 minutes only , one by one for serums/energy.
2. For incence stick you can charge a complete packets commonly used in homes/shops upto 2 minutes one by one for serums/energy.
Once a packet is charged can be used till consumed.