As noted by experts at Drainmaster Scotland , the dramatic fizzing suggests "action," which leads people to believe it’s working even when it isn't. A Better Alternative Story
To assess the effectiveness, mechanism, application method, and limitations of using baking soda (sodium bicarbonate) and vinegar (acetic acid) for clearing sink clogs. baking soda and vinegar for clogged sink
The Ultimate Guide to Clearing a Clogged Sink with Baking Soda and Vinegar As noted by experts at Drainmaster Scotland ,
Quickly cover the drain with the drain plug or a wet rag. This is a crucial step. You want to contain the expanding gas pressure and force it downward against the clog rather than letting it bubble up uselessly into the sink. Let this sit for at least 15 minutes (or up to an hour for stubborn clogs). This is a crucial step