This product is readily available around here and I imagine the company's help line can direct you to stores in your area.

https://www.clorox.com/learn/water-purification-how-much-bleach-purify-water-for-drinking/

Clorox DISINFECTING bleach....not the "no splash" kind. I imagine some "off brand" might be cheaper than Clorox, but you use so little of it...who cares. My thought is that if it disinfects water, it can clean out water containers. But
https://www.clorox.com/learn/how-to-dilute-bleach-for-cleaning/

Clorox's customer support line may be helpful, too. I will tell you this: once opened, the product has a limited effective life. So I purchase it in the smallest quantities I can for disinfection purposes.